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Industrial and agricultural wastewater treatment, which has the potential to cause serious risks to human health and the environment, has special importance at the lowest cost and highest efficiency such as biological processes to treat wastewater. The purpose of the study was removing iron and sulfate from very saline synthetic wastewater by means of halophilic sulfate-reducing bacteria. This process was performed under anaerobic conditions to change wastewater to a chemical fertilizer to use in saline and alkaline soils. Three halophilic SRBs were isolated and purified from wastewater of the cotton delinting factory by Postage C medium which supplemented with sodium chloride and magnesium chloride hexahydrate. The highest NaCl tolerance strain (HSR973) was allocated to Desulfovibrio halophilus sp. This experimental study was conducted in a fluid bed reactor at anaerobic conditions. Diluted concentrations of cotton linters wastewater containing 50–400 ppm iron were added to the reactor. After the bacteria fixation to different iron concentrations, the maximum removal efficiency of iron and sulfate was achieved 85.3 % and 78.4 % at the optimum retention time of 24-hours respectively. Sulfate concentration in samples decreased to about 20 % of initial concentration after 24-h retention time. The highest production of H2S at optimum operational conditions was about 228 ml l−1. The reduction of sulfate and iron biological precipitation by anaerobic rector presented high performance. This removing accompanied with the alkalinity increase during the process which could be improved condition for acidic wastewater treatment. The produced iron sulfide sludge was not suitable for use as a chemical fertilizer due to its lack of complete separation. However, the total sludge produced was able to be consumed in saline and alkaline soils for various purposes after additional treatment., Agricultural science; Agricultural soil science; Agricultural technology; Agricultural water management; Environmental science; Environmental pollution; Biological sciences; Biotechnology; Microbial biotechnology; Nutrient availability; Anaerobic bioreactor, Biological removal, Chemical fertilizer, Cotton delinting factory; Halophilic sulfate-reducing bacteria.

Understanding the forms and dynamics of soil phosphorus (P) is essential to maintain agricultural productivity while minimizing environmental risks. Since it was first used on soil extracts in 1980, 31P-nuclear magnetic resonance spectroscopy (P-NMR) has emerged as the leading technique to characterize extractable soil organic P forms. However, it is still underutilized in agriculture; of the more than 200 soil P-NMR papers published to date, only 44 have been conducted in non-pasture soils used for the production of annual or perennial crops, and only nine of those have linked identified P forms to agronomic parameters such as yield. This paper reviews these prior studies, suggesting gaps in research with respect to cropping systems and geographical regions. In particular, there have been few recent P-NMR studies that have fully identified P forms in African soils, and few studies of permanent crops such as orchards and vineyards. There is a need to link future P-NMR studies of cropping systems to agronomic parameters, and combine P-NMR with other techniques to fully capture P dynamics in cropping systems. Graphical abstract Agricultural field, soil and spectrum from Canada. Spectrum adapted from Cade-Menun et al. [33].

World is changing dramatically. Every sphere of our life is influenced by global climate changes, including agriculture sector. Rising air temperature and temporal variability of rainfall are crucial outcomes of climate changes for agricultural activities. Main impact of these outcomes on agriculture is the change of soil water amount. Soil water is an exclusive resource of water for plants. Changes of soil water storage are sensed very sensitively by farmers. Development of soil water storage was analysed in this paper. The Nitra River catchment is covered by nets of hydrological and meteorological stations of Department of Biometeorology and Hydrology, Slovak University of Agriculture in Nitra. Quantity of available soil water storage for plants was calculated every month in the years from 2013 to 2016. Calculations were done based on real measurements for soil horizon 0-30 cm. Ratio between a real available soil water storage and a potential available soil water storage was specified. Amount of potential available soil water storage was derived by retention curves of soil samples. Map of risk areas was created in GIS in pursuance of these calculations. We can see the negative trends of available soil water storage in years 2015 and 2016. Main addition of this paper is a selection of areas where soil moisture is a limiting factor of agriculture. In these areas, it is necessary to do the mitigation measures for sustainable development of agricultural activities.

The ease with which fertilizers are leached through soils is a growing interest of society, and one with which students should become knowledgeable. This exercise was developed to demonstrate the degree to which N, P, and K fertilizers move through soils of different adsorption and permeability characteristics and under different leaching intensities. Rainfall equivalent to 13 cm did not leach fertilizers through a 60-cm column of dry sandy loam soil. Addition of 54 cm water resulted in leaching 57% of the applied N, 0% P, and 42% of the K. In a related exercise, students are led through a series of calculations to estimate relative mobility of N, P, and K in soil based on routine chemical analysis of column leachate and a surface layer of soil after leaching is completed. On a scale of 1 to 10 (10 = most mobile), mobility was 9.9 for N, 0.1 for P, and 3.3 for K. The results support the common practices of broadcasting N, but banding P and K for maximum efficiency. S GROWING CONCERN of the effects of farming practices on groundwater quality creates an interest in leaching of agricultural chemicals from soil. The importance of movement of fertilizer nutrients with respect to soil type and rainfall environment must be stressed to students planning to work in the agronomic crops area. With this in mind, an exercise was designed to demonstrate leaching and relative mobility in soil of different fertilizer nutrients. Although dyes have commonly been used to demonstrate movement of materials through soils, the leaching of fertilizer nutrients in laboratory exercises has not been reported. Bowman et al. (1988) used a 0.01 M CaCI 2 saturated sand column and dyes to demonstrate miscible displacement and the rapid leaching of CrO42-, which they suggested was similar to movement of NO~.Williams (1985) used anionic (methyl orange) and cationic (methylene blue and basic fuchsin) dyes to demonstrate the effect of soil cation exchange capacity on movement of cations and anions through a sandy soil. Similarly, Butters and Bandaranayake (1993) used cationic and anionic dyes to demonstrate solute transport through soil columns. This exercise consists of placing two soils with differing permeability and nutrient retention capacities into several transparent tubes. Fertilizer compounds are added and columns leached with different amounts of water to represent high rainfall and low rainfall environments. The high rainfall amount is enough to readily leach mobile nutrients through the column of soil while the low rainfall amount is enough to move the wetting front to the end of the tube withD.S. Owens and G.V. Johnson, Dep. of Agronomy, Oklahoma State Univ., Stillwater, OK 74078. Contribution from the Oklahoma Agric. Exp. Stn. Received 23 May 1995. *Corresponding author (gvj@soilwater.agr. okstate.edu). Published in J. Nat. Resour. Life Sci. Educ. 25:i28-131 ( 996). out solution leaving the tube. Water passing through the soil (leachate) is collected in increments that represent fractions of a total pore volume for the soil used. Leachate samples are analyzed. For Part II of the exercise a surface layer of soil is removed for nutrient analysis. This exercise was used in an undergraduate soil fertility course at Oklahoma State University. Objectives for development of the teaching-learning exercise in nutrient mobility were: (i) develop a technique demonstrate fertilizer nutrient movement in the soil, (ii) devise a system of calculations to interpret data obtained from the exercise, and (iii) determine relative nutrient mobility. MATERIALS AND METHODS Part I. Fertilizer Nutrient Leaching Soil Column Preparation Approximate pore volumes for loam and sandy loam soils are determined by weighing a 100-mL graduated cylinder, and then adding dry soil while gently tapping the cylinder on the lab bench top until the cylinder is filled. The cylinder plus soil is then weighed and soil weight calculated. Bulk density (BD) is calculated by dividing the weight of the soil (g) by the volume (100 cm3). Assuming a particle density (PD) of 2.65 gcm-3, the percentage of soil volume occupied by solids is then given by (BD/PD)I00 = % solids. The percent porosity is determined by subtracting the percent solids from 100. The soil columns are created by filling capped transparent plastic tubes (100 cm long by 4.34 cm i.d.; part no. BL 1750; Giddings Machine Co., Ft. Collins, CO) to a depth of 60 cm from the bottom with dry soil. When filling the tubes with loam or sandy loam soils, the students should lightly tap the colunms to try to approximate the packing of soil in the 100-mL graduated cylinder when bulk density was determined. A filter paper disc slightly smaller than the tube diameter is placed on the soil surface to reduce soil mixing when solution is added to the columns. The tubes are placed on a display rack and labeled to identify the following fertilizer leaching conditions: L/LR/C, L/LR/F, L/HRJC, L/HR/F, S/LR/C, S/LR/F, S/HR/C, S/HR/F, where L = loam, S = sandy loam, LR = low rainfall, HR = high rainfall, C = control, and F = fertilized. The pore volume of each column will equal the volume of soil column (V = rcr2 L) times the porosity. Fertilizer Preparation and Addition The solution containing fertilizer nutrients is prepared to approximate a 224 kg ha-~ (200 lb acre-r) fertilizer addition of each nutrient. To 400 mL of distilled water (enough for 10 replications), 618 mg of (NH4)2HPO4, 573 mg Abbreviations: ICAP, induction coupled argon plasma. 128 d. Nat. Resour. Life Sci. Educ., VoL 25, no. 2, 1996 NH4NO3, and 528 mg of KCl were added,. For nitrogen (N), phosphorous (as P205), and potassium, (as K20) a total 33.2 mg of each will be contained in a 40-mL volume. In terms of the elemental concentration the 40 mL additions represent 23.1 mg NH4-N, 10 mg NO3-N, 14.5 mg P, and 27.8 mg K. Students add the fertilizer solution to each of the fertilized columns of soil and 40 mL of distilled water to the control columns then observe the downward movement of the wetting front. After the wetting front appears to have stopped (48 h), the front is marked by making a line on the tube. The distance from the soil surface is measured and recorded. Inverted beakers placed over the column tops minimizes evaporative loss of solutions. Development of the exercise to this point may be accomplished in a 2-h lab period. Leaching the Columns Distilled water is added to soil columns to simulate rainfall. An amount equal to one-half a pore volume is added to each of the low rainfall treatments. Funnels and leachate collection containers (marked to indicate one-fourth leaching volumes) are placed under the high rainfall treatment soil columns. Water is periodically added to maintain a "head" on the top of these columns until a total of two pore volumes have been applied. Students observe the collection of leachate in the containers below the soil columns. After each one-fourth pore volume leaches through, another empty container (calibrated) is placed under the column and the collected leachate is poured into a graduated cylinder, the volume recorded, and a portion transferred to an analysis sample container and labeled. Anticipate rapid leaching in the sandy loam soil and much slower leaching in the loam soil. A collection of four or five one-fourth pore volumes will be sufficient. Technically there is enough water for eight one-fourth pore volumes but, about one-half pore volume will remain in the columns at field capacity. Because the loam soil will leach much slower, someone will have to monitor the columns throughout the day until enough onefourth pore volumes leach through. It is not highly critical that the collected samples measure exactly one-fourth pore volume but they should not vary greatly. When all the samples are obtained and labeled appropriately, they are sent to the laboratory for analysis. The laboratory used automated flow injection analysis (Lachat, 1989, 1990) for NH~-and NO]-N, colorimetric (phosphomolybdenum blue) analysis of P and atomic emission spectrophotometric analysis (ICAP) of K for solutions. Soil was extracted using a saturated CaSO4 solution for NOy-N, and Mehlich-3 (Mehlich, 1984) for P and K. However, these extraction and analytical methods are not unique to the success of this exercise. Any reliable analytical method, and any extraction method that is capable of extracting the chemical form of the nutrient added, will be acceptable. Interpreting the Data When the laboratory analysis is completed, laboratory data sheets (reporting nutrient concentrations in ppm) together with several tables and graph paper are made available to the students. The students must follow stepwise calculations through the series of tables to determine how Table I. Concentration of nutrients leached through fertilized (F) and

According to problems of soil and water loss and soil degraded in red soil hillslope land exploitation of southern China, based on the research of investigation and trial, and taking Fujian province as an typical representative example, this paper systematically analyzed exploiting scale, current situation and a series eco-problems of soil and water conversation in recent years, revealed the mechanism of how hillside orchards loss happened and developed, defined the key period and key parts of topography, analyzed the cause of senescence of fruiters. On the theory of Ecological economics and sustainable development, the basis of reasonable exploitation and utilization of hillslope land resource, the paper proposed scientific planning, insisted on local conditions, promoted exploited quality, enhanced management of young orchards, carried on new technology of soil and water conversation, increased land coverage, controlled soil and water loss, built up comprehensive treatment of sustainable development and countermeasure of ecological regulation to eco-orchards.

With consideration of the decentralization of wheat fertilization management and status in quo in Henan province, the paper mainly designed county wheat decision-making System of survey and directions for soil Based on GIS. By collecting 3773 records of survey and directions for soil in 976 vilages, Hua county, protracting all kinds of vectorgraphs about villages, towns and the soil survey points, and using nutrient balance and model of survey and directions for soil and wheat fertilization directions, the paper had analysed and designed the system of survey and directions for soil and wheat fertilization directions integrating OOP, software component technique, GIS and so on, realized query for information of soil survey points and estimation for soil nutrient distribution and decision-making for wheat fertilization directions, and provided technology support for application of crop survey and directions for soil in Henan province.

Heavy metal contamination in soil is an important factor affecting the determination of safe redevelopment methods for industrial and mining land. In this paper, the soil environment of a typical mining city in northern China was taken as the research object, 148 surface soil samples were collected and the contents of heavy metals were measured. The health risk classification criteria for heavy metal contamination of soils and the method of priority assessment for redevelopment were used. The results showed that: the risk of potential utilization types of heavy metals in the abandoned industrial and mining land is different. When the utilization type is agricultural land, the soil environmental quality is good as a whole, and a small number of plots are polluted by cadmium (Cd)and mercury (Hg); When the land use type is construction land, the risk of heavy metal pollution comes from chromium (Cr); The priority of development in this study area is as follows: agricultural land > construction land > ecological land.

Microbial community functional diversity is a sensitive indicator of soil quality, soil management such as tillage and crop residue which can affect the microbial community functional diversity of paddy field. However, there is still limited information about the influence of different tillage and crop residue management on rhizosphere soil microbial community functional diversity in a double-cropping rice (Oryza sativa L.) field. Therefore, four tillage treatments were set up in paddy field, tillage treatments were included: conventional tillage with residue incorporation (CT), rotary tillage with residue incorporation (RT), no-tillage with residue retention (NT), and rotary tillage with residue removed as control (RTO). And the effects of CT, RT, NT, and RTO treatments on the average well color development (AWCD), genetic diversity indices and carbon source utilization of rhizosphere soil were studied in the present paper. The results showed that the values of AWCD with CT, RT and NT treatments were higher than that of RTO treatment. It was implied that application of crop residue management resulted in the variation of the carbon utilization efficiency of rhizosphere soil microbial communities. At maturity stages of early and late rice, the Richness indices, Shannon indices and McIntosh indices with CT treatment were significantly higher than that of RTO treatment, and with the order as CT>RT>NT>RTO. Principal component analysis (PCA) results indicated that there were significant differences in carbon substrate utilization patterns among different tillage treatments. Carbohydrates and amino acids were the main carbon resources utilized by rhizosphere soil microbes. Therefore, the combined application of tillage with crop residue management could significantly increase the rhizosphere soil microbial community functional diversity in the double-cropping paddy field of southern China.

Soil microorganism plays an important role in nitrogen (N) fixation process of paddy field, but the related information about how soil microorganism that drive N fixation process response to change of soil phy-chemical characteristics under the double-cropping rice (Oryza sativa L.) paddy field in southern of China is need to further study. Therefore, the impacts of 34-years different long-term fertilization system on soil N-fixing bacteria community under the double-cropping rice paddy field in southern of China were investigated by taken chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) method in this paper. The field experiment were set up four different fertilizer treatments: chemical fertilizer alone (MF), rice straw and chemical fertilizer (RF), 30% organic manure and 70% chemical fertilizer (OM), and unfertilized as a control (CK). This results showed that compared with CK treatment, the diversity index of cbbLR and nifH genes with OM and RF treatments were significantly increased (pcbbLR gene with OM, RF and MF treatments were increased by 23.94, 12.19 and 6.70×107 copies g-1 compared to CK treatment, respectively. Compared with CK treatment, the abundance of nifH gene with OM, RF and MF treatments were increased by 23.90, 8.82 and 5.40×109 copies g-1, respectively. This results indicated that compared with CK treatment, the soil autotrophic azotobacter and nitrogenase activities with OM and RF treatments were also significantly increased (p

Sub-Saharan Africa is faced with the challenge of improving current food security on highly degraded land. At the same time, the region has to develop strategies to ensure future food security for the increasing population under worsening climate change. Conventional tillage (CT) has for many years resulted in the deterioration of soil quality through depletion of soil organic matter. This review of literature provides an overview of the impact of conservation agriculture (CA) on soil quality with particular emphasis on key soil physical, chemical and biological properties. This paper also discusses impact of CA on yield, highlighting South African research gaps since the adoption is still very low in the country. The review of numerous studies indicated that soil quality and yield improvements are possible in CA although some negative results have also been reported under contrasting environments. Yield under CA were recognised to be resilient to seasonal rainfall variability compared with CT because of its ability to conserve water. CA is particularly relevant to the South African maize production given high levels of soil degradation, water scarcity and low soil fertility status. This review of literature demonstrated that CA can have substantial positive environmental, financial, social and health benefits for South Africa and the world. However, more research on CA is required from different agroecological zones and socio-economic contexts since maize is the biggest produced crop in South Africa.

This paper aimed at using the niche-fitness analysis method to assess soil fertility of cultivated land in Jianghan Plain in China. By introducing the niche-fitness theory into comprehensive analysis of soil fertility, an evaluation method was developed using geographic information systems (GIS) and the soil basic niche-fitness model (SBNFM). To begin with, 10 indicators were selected and used to assess the spatial differences of soil fertility for cultivated land, and its weight was decided using analytic hierarchy process (AHP). Soil samples were collected from topsoil (0–25 cm) in 58 units and examined for pH, organic matter (OM), total nitrogen (TN), etc. After standardizing soil attribute data of each unit, the optimum niche of every indicator was obtained and the soil basic niche-fitness value of each plot was calculated by using SBNFM. Finally, the soil fertility of the cultivated land was divided into four grades based on the shortest distance cluster analysis method in this area. Results ...

Development of no-tillage (NT) farming has revolutionized agricultural systems by allowing growers to manage greater areas of land with reduced energy, labour and machinery inputs to control erosion, improve soil health and reduce greenhouse gas emission. However, NT farming systems have resulted in a build-up of herbicide-resistant weeds, an increased incidence of soil- and stubble-borne diseases and enrichment of nutrients and carbon near the soil surface. Consequently, there is an increased interest in the use of an occasional tillage (termed strategic tillage, ST) to address such emerging constraints in otherwise-NT farming systems. Decisions around ST uses will depend upon the specific issues present on the individual field or farm, and profitability and effectiveness of available options for management. This paper explores some of the issues with the implementation of ST in NT farming systems. The impact of contrasting soil properties, the timing of the tillage and the prevailing climate exert a strong influence on the success of ST. Decisions around timing of tillage are very complex and depend on the interactions between soil water content and the purpose for which the ST is intended. The soil needs to be at the right water content before executing any tillage, while the objective of the ST will influence the frequency and type of tillage implement used. The use of ST in long-term NT systems will depend on factors associated with system costs and profitability, soil health and environmental impacts. For many farmers maintaining farm profitability is a priority, so economic considerations are likely to be a primary factor dictating adoption. However, impacts on soil health and environment, especially the risk of erosion and the loss of soil carbon, will also influence a grower's choice to adopt ST, as will the impact on soil moisture reserves in rainfed cropping systems.

The ability to accurately measure the geometric characteristics of soil wetted bodies (SWBs) is very important for conserving water in agriculture. However, measurements of SWBs obtained using conventional methods have a number of defects. Ground penetrating radar (GPR) is a promising technique for detecting buried features. In this paper, we used GPR to nondestructively investigate SWBs formed under drip irrigation. First, numerical simulations were performed to obtain the theoretical radar-gram of SWBs. Then, controlled irrigation experiments were performed to obtain radar scan datasets in a laboratory. The GPR image was interpreted according to the numerical simulation results, and the SWB thickness detection accuracy was estimated. Finally, GPR detection was performed in the field with different irrigation volumes, and the detection effect was assessed. The GPR reflections in the laboratory and field measurements were more complex than in the numerical simulation images, but the location and thickness of SWBs were still clear; the accuracy of the measured thickness was high, and the accuracy decreased with an increase in irrigation volume. The radar image resolution and thickness accuracy measured in the field were slightly less than the values measured in the laboratory. Thus, GPR is able to quickly and accurately characterize SWBs formed by drip irrigation based on the thickness and relative position in the soil. Furthermore, the F-K offset transformation was an effective GPR data processing method for focusing reflections from SWBs to obtain their true position and physical extent.

Background and aims This paper was primarily devoted to understand the interactions of soil aggregates, organic carbon (C) and carbon cycle enzymes in aggregates under different fertilization managements, aiming to identify the effects of organic and inorganic fertilizer amendments on soil organic C accumulation and the activities of carbon cycle enzymes within aggregates in Vertisol. Methods A Vertisol soil following 4-year compost and inorganic fertilizer amendments, i.e. no fertilizer (CK), mineral fertilizer (FR) and 60% compost N plus 40% fertilizer N (FRM), was collected to identify the dynamics of organic C, enzymes activities and their associations with macroaggregation using aggregate fractionation techniques. Results The organic C content in all FR and FRM treatments was 8.24–41.15% higher than that in CK. An increased amounts of carbon cycle enzymes in aggregates or 0–20 cm bulk soil were also observed in FRM plots. Compared to FR, FRM significantly strengthened the structural stability of macroaggregates and the intimate connection between enzyme activities and macroaggregates. Conclusions As a recommended measure, supplementation with organic manure such as compost strengthened the process of mutual promotion between carbon cycle enzymes and macroaggregates, and the synergistic effect would be highly beneficial to soil organic C sequestration.

3 5 INTRODUCTION 3 6 MATERIALS AND METHODS 39 RESULTS AND DISCUSSION 46 Soil Growing Degree Days 46 Soil Water Content 57 Soil Air-Filled Porosity 57 Soil Water Desorption Characteristic 62 Soil Penetration Resistance 65 CONCLUSION 68 REFERENCES 69 GENERAL SUMMARY 72 ADDITIONAL REFERENCES 75 iv ACKNOWLEDGEMENTS 77 APPENDIX A: RIDGE SHAPES BUILT WITH DIFFERENT TREATMENTS 78 APPENDIX B; ADDITIONAL STATISTICAL INFORMATION (PAPER I) 82

Studying soil nutrient variability and its effect on the growth and development of crops under a traditional tillage mode is the foundation for comprehensively implementing precision agriculture policies at the field scale and ensuring excellent crop management. In this paper, a 28.5 hm2 winter wheat field under the traditional cultivation model in Tianzhuang town of Huantai County was selected as the research area. The mesh point method was utilized for sampling (60×60 m), and the characteristics of soil available nitrogen (AN), available phosphorus (AP) and available potassium (AK) variations in the before sowing, reviving, jointing, and filling stages of winter wheat were analyzed using geostatistical and GIS methods. Moreover, Pearson correlation analysis was used to study the response of wheat growth and development to soil nutrient variations. As the growth stages progressed, 1) each nutrient showed the characteristics of low-high-low and moderate variability. The highest AN and AK contents were found at the reviving stage, while AP reached a turning point at the jointing stage. The order of variability of each nutrient was AN>AP>AK. 2) The nutrient variations first increased and then decreased and showed medium to strong spatial correlation. The three nutrients were strongly spatially correlated in the before sowing stage and moderately spatially correlated during the reviving stage. During the jointing and filling stages, AN had moderate spatial correlation, and AP and AK had strong spatial correlation. The spatial correlation of each nutrient was the weakest in the reviving stage, and the spatial correlation of AN was strongest in the before sowing stage, while the spatial correlations of AP and AK were strongest in the jointing stage. The spatial correlation of each soil nutrient decreased from the before sowing stage to the reviving stage and from the jointing stage to the filling stage, and the spatial correlation increased from the reviving stage to the jointing stage. 3) The soil nutrient content first increased and then decreased, and the grades of the nutrients gradually decreased. 4) The correlation between soil nutrients and wheat growth gradually increased. AN had the highest correlation with wheat growth, followed by AK and AP. The effect of soil nutrients on the growth of wheat at the reviving stage was greater than the effect of nutrients in the current stage. The growth of wheat at the jointing stage was mainly influenced by nutrients in the current stage, while the growth of wheat at the filling stage was influenced by the nutrient contents of both the previous and current stages. Thus, the date of fertilizer supplementation should be postponed properly. In this study, the soil nutrient dynamics and their influence on the growth of wheat during the winter wheat growth period under the traditional field model were well described, and these results could provide a theoretical basis for the precision management of soil nutrients in the northern winter wheat area where the planting environment and cultivation management are relatively uniform.

The aim of this work was to develop a method for selection of optimal soybean varieties for the American Midwest using data analytics. We extracted the knowledge about 174 varieties from the dataset, which contained information about weather, soil, yield and regional statistical parameters. Next, we predicted the yield of each variety in each of 6,490 observed subregions of the Midwest. Furthermore, yield was predicted for all the possible weather scenarios approximated by 15 historical weather instances contained in the dataset. Using predicted yields and covariance between varieties through different weather scenarios, we performed portfolio optimisation. In this way, for each subregion, we obtained a selection of varieties, that proved superior to others in terms of the amount and stability of yield. According to the rules of Syngenta Crop Challenge, for which this research was conducted, we aggregated the results across all subregions and selected up to five soybean varieties that should be distributed across the network of seed retailers. The work presented in this paper was the winning solution for Syngenta Crop Challenge 2017.

For the efficient utilization of soil and water resources, soil testing of such farm was carried out in Nashik. Makhamalabad farm for providing comprehensive information was characterized. Representative soil samples from each of forteen plots of Makhamalabad farm were collected. The soil survey of representative area was completed by plane table survey method. The soil samples were tested in laboratory for determining various soil properties viz., soil pH, soil electrical conductivity, soil colour, available moisture content and soil nutrients like organic carbon content, soil calcium carbonate, available nitrogen, available potassium and available phosphorus. The chemical analysis of soil will measure the nutrient status of the soil and serve as a guide to profitable use of fertilizers and recommendation of crops. A standard soil fertility map is a two dimensional document presented on a paper or on various other kind of supports and gives greatly reduced, simplified pictures of the spatial organization of soils in the natural environment showing the soil properties and available soil nutrients. The work is carried out for preparation of soil fertility map of Makhamalabad farm which belongs to K.K. Wagh Education Society, Nashik. The Makhamalabad farm is situated in the Makhamalabad shivar, Nashik. The area of farm was about 9.31 ha. There are 14 plots in the farm.

In recent years, the mechanized soil compaction is becoming increasingly prominent problem with the rapid increase of agricultural mechanization level. The paper expounded that soil compaction influenced on soil environment including bulk density, hardness, porosity of soil, which resulted in soil structural characteristics change and soil quality degradation, it went against crops production. The improvement measures were proposed including agronomic measures, field craft measures, tractors driving and walking device technological improvement measures and loose soil measures for soil compaction.

The precision agriculture (PA) is the end product of the modern high tech's information technology and the agricultural production technology union. The soil nutrients are not only an important component of soil research, but also a critical determinant of its productivity. Some soil nutrients spatial distribution pictures were established based on important factors that affect crops production. The soil nutrient situation was understood by the paper in Jilin province black soil. The results can realized some information opening and sharing and helped some farmer and manager to understand some soil nutrient spatial distribution. They can speed up the development of Jilin province’s precision agriculture.

Power demands are set to increase by two-fold within the current century and a high fraction of that demand should be met by carbon free sources. Among the renewable energies, solar energy is among the fastest growing; therefore, a comprehensive and accurate design methodology for solar systems and how they interact with the local environment is vital. This paper addresses the environmental effects of solar panels on an unirrigated pasture that often experiences water stress. Changes to the microclimatology, soil moisture, water usage, and biomass productivity due to the presence of solar panels were quantified. The goal of this study was to show that the impacts of these factors should be considered in designing the solar farms to take advantage of potential net gains in agricultural and power production. Microclimatological stations were placed in the Rabbit Hills agrivoltaic solar arrays, located in Oregon State campus, two years after the solar array was installed. Soil moisture was quantified using neutron probe readings. Significant differences in mean air temperature, relative humidity, wind speed, wind direction, and soil moisture were observed. Areas under PV solar panels maintained higher soil moisture throughout the period of observation. A significant increase in late season biomass was also observed for areas under the PV panels (90% more biomass), and areas under PV panels were significantly more water efficient (328% more efficient).

Population growth and climate change challenge our food and farming systems and provide arguments for an increased intensification of agriculture. A promising option is eco-functional intensification through organic farming, an approach based on using and enhancing internal natural resources and processes to secure and improve agricultural productivity, while minimizing negative environmental impacts. In this concept an active soil microbiota plays an important role for various soil based ecosystem services such as nutrient cycling, erosion control and pest and disease regulation. Several studies have reported a positive effect of organic farming on soil health and quality including microbial community traits. However, so far no systematic quantification of whether organic farming systems comprise larger and more active soil microbial communities compared to conventional farming systems was performed on a global scale. Therefore, we conducted a meta-analysis on current literature to quantify possible differences in key indicators for soil microbial abundance and activity in organic and conventional cropping systems. All together we integrated data from 56 mainly peer-reviewed papers into our analysis, including 149 pairwise comparisons originating from different climatic zones and experimental duration ranging from 3 to more than 100 years. Overall, we found that organic systems had 32% to 84% greater microbial biomass carbon, microbial biomass nitrogen, total phospholipid fatty-acids, and dehydrogenase, urease and protease activities than conventional systems. Exclusively the metabolic quotient as an indicator for stresses on microbial communities remained unaffected by the farming systems. Categorical subgroup analysis revealed that crop rotation, the inclusion of legumes in the crop rotation and organic inputs are important farming practices affecting soil microbial community size and activity. Furthermore, we show that differences in microbial size and activity between organic and conventional farming systems vary as a function of land use (arable, orchards, and grassland), plant life cycle (annual and perennial) and climatic zone. In summary, this study shows that overall organic farming enhances total microbial abundance and activity in agricultural soils on a global scale.

Since prehistoric times, farmers have faced the challenge of balancing the demand for increasing food production from existing soil resources with conservation of these resources. Land use change from natural vegetation to agricultural land and intensification of agricultural soil management are closely linked to increased rates of soil erosion. This review analyzed and quantified the effects of changes in past land use and agricultural soil management on soil erosion. At a global scale, the period of the first significant land use change closely corresponds to a first wave of soil erosion. Equally important, however, are changes in past soil management. As shown by numerous case studies, changes in management under the same land use can convert sustainable agroecosystems into highly degraded systems. As soil erosion rates, soil profile truncation, agricultural yield, and biomass production are closely related, considering the interactions and feedback effects is important when modelling this system. This paper shows how modelling the dynamics of past soil erosion and agricultural sustainability raises similar challenges to those of quantifying future changes in climate or agricultural systems., This research was funded under the research projects “AGL2012-40128-C03-01”,“AGL2012-40128-C03-02” and “AGL2012-40128-C03-03”. The first author is grateful for the funding by the Ministry of Economy and Competitiveness under the Ramon y Cajal Fellowship programme.

This paper gives a glance about the conservation agriculture concept and the worldwide increase of agricultural area where this technique has been adopted. The main constraints to agricultural production in the Mediterranean region are discussed, highlighting the importance of conservation agriculture to mitigate them. Results of long term studies with this technique, in Portugal, showed an increase in organic matter, the improvement of aggregates stability and the continuity of biological porosity along the soil profile. These changes of soil properties are helping to overcame edaphic and climatic constrains under Mediterranean conditions. The saturated hydraulic conductivity is improved allowing a better drainage during wet winters, and together with higher soil cohesion the transitability of the soil is enhanced, allowing a correct timing of field operations like nitrogen top dressing and herbicides application. Nitrogen use efficiency is improved either by the timing of application and by the improvement of soil organic matter content. Soil productivity is also enhanced and the overall energy use efficiency is double when soil organic matter content is raised from 1 to 2% in the top 30 cm of the soil. Therefore, conservation agriculture is advantageous from the economic and environmental point of view contributing for the sustainability of rainfed agriculture.

Agricultural activities have drastically increased soil erosion rates and it is therefore likely to have important effects on the Earth's Critical Zone. In this paper we first investigate to what extent agricultural soil erosion can be quantified. We then combine this information with our current understanding of Critical Zone processes to assess the impact of agricultural soil erosion on soil functioning (biogeochemical cycling, hydrology, crop productivity) and to identify areas where additional research is needed to complete our understanding of how agricultural soil erosion affects the Earth's Critical Zone at different spatial and temporal scales.

The development of cultivars with an improved nitrogen use efficiency (NUE) together with the application of plant growth-promoting bacteria is considered one of the main strategies for reduction of fertilizers use. In this sense, this study: i) evaluated the effect of Azospirillum brasilense on the initial development of maize genotypes; ii) investigated the influence of A. brasilense inoculation on NUE under nitrogen deficit; and iii) sought for more NUE genotypes with higher responsiveness to A. brasilense inoculation. Twenty-seven maize genotypes were evaluated in three independent experiments. The first evaluated the initial development of maize genotypes with and without A. brasilense (strain Ab-V5) inoculation of seeds on germination paper in a growth chamber. The second and third experiments were carried out in a greenhouse using Leonard pots and pots with substrate, respectively, and the genotypes were evaluated at high nitrogen, low nitrogen and low nitrogen plus A. brasilense Ab-V5 inoculation. The inoculation of seeds with A. brasilense Ab-V5 intensified plant growth, improved biochemical traits and raised NUE under nitrogen deficit. The inoculation of seeds with A. brasilense can be considered an economically viable and environmentally sustainable strategy for maize cultivation.

This paper analyses a local innovation in response to intense soil degradation in olive orchards of north-west Syria. Farmers developed a practice consisting of quarrying red clayey soil in valley bottoms and applying this soil to hillslope olive orchards with heavily degraded calcareous soils. A biophysical, economic and social analysis of the practice of soil application identified the opportunities and risks of this innovative soil management technique. On the basis of a pairwise comparison of nine adjacent treated and nontreated orchard plots, soil applications were found to increase soil depth by 36%, soil water availability by 28% and total available soil nutrients: potassium (+45%), nitrogen (+12%) and phosphorus (+6%). Olive yield increased by about 40%. A cost–benefit analysis found this practice to be economically viable within a large geographical area, and farmers scored the practice higher than alternative methods. A socio-economic analysis revealed its widespread adoption among different farmer types. The positive results of soil applications at the farm level explain its fast adoption. However, potential risks – including the further depletion of soil resources and the transfer of soil-borne diseases – limit the long-term sustainability of this locally developed practice. Copyright © 2013 John Wiley & Sons, Ltd.

Small-holding farmers in the developing world suffer from sub-optimal crop yields because they lack a soil diagnostic system that is affordable, usable, and actionable. This paper details the fabrication and characterization of an integrated point-of-use soil-testing system, comprised of disposable ion-selective electrode strips and a handheld electrochemical reader. Together, the strips and reader transduce soil ion concentrations into to an alphanumeric output that can be communicated via text message to a central service provider offering immediate, customized fertilizer advisory. The solid-state ion-selective electrode (SSISE) strips employ a two-electrode design with screen-printable carbon nanotube ink serving as the electrical contacts for the working and reference electrodes. The working electrode comprises a plasticizer-free butyl acrylate ion-selective membrane (ISM), doped with an ion-selective ionophore and lipophilic salt. Meanwhile, the reference electrode includes a screen-printed silver-silver chloride ink and a polyvinyl-butyral membrane, which is doped with sodium chloride for stable reference potentials. As a proof of concept, potassium-selective electrodes are studied, given potassium's essential role in plant growth and reproduction. The ISE-based system is reproducibly manufactured to yield a Nernstian response with a sub-micromolar detection limit (pK+ of 5.18 ± 0.08) and near-Nernstian sensitivity (61 mV/decade) in the presence of a 0.02 M strontium chloride extraction solution. Analysis of soil samples using the printed electrodes and reader yielded a correlation coefficient of R2 = 0.89 with respect to values measured via inductively coupled plasma atomic emission spectroscopy (ICP-AES). The reliable performance of this system is encouraging toward its deployment for soil nutrient management in resource-limited environments., Massachusetts Institute of Technology. Tata Center for Technology and Design, National Science Foundation (U.S.) (award number DMR-1419807)

Since the late 1970s, transitions in socioeconomic status and new governmental policies have led to drastic changes in agricultural land use types and farm management practices across rural China, such as an increase in the area of land cultivated for cash-crops (e.g. vegetables and orchards) and intensive fertilization and irrigation of this land. How this more intensive management and land use for the more profitable cash crops affects soil nutrients is of great concern for carbon, soil and water quality management In this paper, we attempted to assess the influence of cash crop ecosystems on soil nutrients in the catchment upstream of the Guanting Reservoir, in the Beijing municipality, North China plain. Soil nutrients in cash crop (orchard and vegetable) ecosystems with between 8 and 20 years of intensive management history were compared with traditional agro-ecosystem management patterns (corn and soybean). Results showed that soil organic carbon (SOC) had improved, and total nitrogen (N), and available phosphorus (P) concentrations had marginally increased under intensive management practices in the vegetable and orchard ecosystems in the last 25 years. The increases in SOC and total P densities at the 100 cm soil depth in orchard, vegetable and irrigated corn systems were greater than those in the rain fed corn and soybean systems. Soil available P and electrical conductivity (EC) were highest in the vegetable lands. However, no significant changes were found between the soil physical properties (i.e. bulk density, clay content and water stable aggregate content) of the traditional and cash-cropping systems. Multi regression analysis showed that manure and mineral fertilizer contributed significantly to the increase in soil nutrients. Intensively managed orchards are a better option for improving soil quality and SOC sequestration. However, the risks of nonpoint source pollution from, and soil salinization in, the land used for vegetable cultivation should be considered in the future. (c) 2012 Elsevier B.V. All rights reserved.

In this paper, investigations on agricultural and forestry soil and on water quality assessment were carried out in a natural wetlands reserve, at valley of a mountain, near at the sea and under hydraulic risk (the coast of the Etruschis), in central Italy; Physical-chemical parameters were measured by taking samples of soil on two fields cultivated with an artichoke bed and respectively managed with organic and conventional techniques adjacent the natural wetlands reserve and destined to a controlled development of the agriculture, to protect the reserve. These parameters were also measured on forestry soil inside the reserve and CO2 storage on soil was evaluated. The water chemical analysis of the two ponds inside the reserve was also carried out. The soil managed with organic farming has showed higher chemical fertility. Both organic and conventional field showed high level of soil compaction susceptibility evidenced by high values of penetration resistance and shear strength; while porosity and hydraulic conductivity presented low values. The research highlights that the ecological land use can influence and improve the environmental quality. In fact thanks to the higher organic matter content into the soil, the average values of stored CO2 show that the organic (ΔCOT = 1200 kg·ha–1) and forestry (ΔCFT =2200 kg·ha–1·year–1) treatments have stored higher amount of organic carbon in the soil with respect to the conventional one. Organic matter and dry bulk density can be considered good indicators of the soil quality. The results of the water chemical analysis show a good quality of the brackish water of the ponds situated in the wetlands reserve.

This paper describes the methods used to assess soil fertility and model soil productivity for agricultural land in the Czech Republic. The assessment is based on the obtained crop yields and the various factors that influence those yields. These factors incorporate the physical characteristics of the soil, the climate and the applied agricultural practices. They have been quantified from monitoring ∼500 homogeneous plots of land covering a total area of 9200 ha since 2002. Soil productivity has been modelled using crop yield and crop production functions. A linear production function has been developed through factor analysis. The presented example details wheat production under average conditions for the Czech Republic. It is possible to use the crop production function to improve our understanding of the soil system, as well as for better identification of soil characteristics for economic and environmental purposes.

The widespread use of superabsorbent polymers (SAPs) in arid regions improves the efficiency of local land and water use. However, SAPs' repeated absorption and release of water has periodic and unstable effects on both soil's physical and chemical properties and on the growth of plant roots, which complicates modeling of water movement in SAP-treated soils. In this paper, we proposea model of soil water movement for SAP-treated soils. The residence time of SAP in the soil and the duration of the experiment were considered as the same parameter t. This simplifies previously proposed models in which the residence time of SAP in the soil and the experiment's duration were considered as two independent parameters. Numerical testing was carried out on the inverse method of estimating the source/sink term of root water uptake in the model of soil water movement under the effect of SAP. The test results show that time interval, hydraulic parameters, test error, and instrument precision had a significant influence on the stability of the inverse method, while time step, layering of soil, and boundary conditions had relatively smaller effects. A comprehensive analysis of the method's stability, calculation, and accuracy suggests that the proposed inverse method applies if the following conditions are satisfied: the time interval is between 5 d and 17 d; the time step is between 1000 and 10000; the test error is ≥ 0.9; the instrument precision is ≤ 0.03; and the rate of soil surface evaporation is ≤ 0.6 mm/d.

BACKGROUND AND AIMS Simple indicators of crop and cultivar performance across a range of soil types and management are needed for designing and testing sustainable cropping practices. This paper determined the extent to which soil chemical and physical properties, particularly soil strength and pore-size distribution influences root elongation in a wide range of agricultural top soils, using a seedling-based indicator. METHODS Intact soil cores were sampled from the topsoil of 59 agricultural fields in Scotland, representing a wide geographic spread, range of textures and management practices. Water release characteristics, dry bulk density and needle penetrometer resistance were measured on three cores from each field. Soil samples from the same locations were sieved, analysed for chemical characteristics, and packed to dry bulk density of 1.0 g cm(-3) to minimize physical constraints. Root elongation rates were determined for barley seedlings planted in both intact field and packed soil cores at a water content close to field capacity (-20 kPa matric potential). KEY RESULTS Root elongation in field soil was typically less than half of that in packed soils. Penetrometer resistance was typically between 1 and 3 MPa for field soils, indicating the soils were relatively hard, despite their moderately wet condition (compared with

This paper discusses the effects of trees on soil fertility, with a focus on agricultural systems in Amazonia. Relevant literature concerning the effects of trees on soil physical and chemical properties in tropical, subtropical, and temperate regions is reviewed, covering both natural ecosystems and agroecosystems. Soil carbon, in the form of organic matter, is considered as an indicator of biological activity as well as in relation to policy issues such as carbon sequestration and climate change. In the case of tropical soils and Amazonia, information on the effects of trees on soils is discussed in the context of traditional agriculture systems, as well as in regard to the development of more sustainable agricultural alternatives for the region. Lastly, attention is given to a case study in the savanna region of Roraima, northern Brazil, where a chronosequence of indigenous homegarden agroforestry systems showed clear effects of management practices involving trees on soil fertility. The use of diverse tree species and other practices employed in agroforestry systems can represent alternative forms of increasing soil fertility and maintaining agricultural production, with important practical applications for the sustainability of tropical agriculture. © 2012 Rachel C. Pinho et al.

Due to continuous decreases in arable land area and continuous population increases, Chinese soil scientists face great challenges in meeting food demands, mitigating adverse environmental impacts, and sustaining or enhancing soil productivity under intensive agriculture. With the aim of promoting the application of soil science knowledge, this paper reviews the achievements of Chinese scientists in soil resource use and management, soil fertility, global change mitigation and soil biology over the last 30 years. During this period, soil resource science has provided essential support for the use and exploitation of Chinese soil resources, and has itself developed through introduction of new theories such as Soil Taxonomy and new technologies such as remote sensing. Soil fertility science has contributed to the alleviation and elimination of impeding physical and chemical factors that constrain availability of essential nutrients and water in soils, the understanding of nutrient cycling in agroecosystems, and the increase in nutrient use efficiency for sustainable crop production. Chinese soil scientists have contributed to the understanding of the cropland's role in global change, particularly to the understanding of methane and nitrous oxide emission from rice fields and the effect of elevated carbon dioxide and ozone on rice-wheat system. Soil biology research has progressed in biological N fixation, distribution of fauna in Chinese soils, and bioremediation of polluted soils. A new generation of soil scientists has arisen in the last three decades. The gaps between research and application in these soil science fields are also discussed.

The effect of no- and reduced tillage (NT/RT) on greenhouse gas (GHG) emission was highly variable and may depend on other agronomy practices. However, how the other practices affect the effect of NT/RT on GHG emission remains elusive. Therefore, we conducted a global meta-analysis (including 49 papers with 196 comparisons) to assess the effect of five options (i.e. cropping system, crop residue management, split application of N fertilizer, irrigation, and tillage duration) on the effect of NT/RT on CH4 and N2O emissions from agricultural fields. The results showed that NT/RT significantly mitigated the overall global warming potential (GWP) of CH4 and N2O emissions by 6.6% as compared with conventional tillage (CT). Rotation cropping systems and crop straw remove facilitated no-tillage (NT) to reduce the CH4, N2O, or overall GWP both in upland and paddy field. NT significantly mitigated the overall GWP when the percentage of basal N fertilizer (PBN) >50%, when tillage duration > 10 years or rainfed in upland, while when PBN

This paper presents a novel analytical framework to assess soil quality, incorporating bacterial community structure data derived from PCR-DGGE analysis into a principal component analysis, along with a total of 23 other physical, chemical, and biotic soil variables. This framework was applied to a slash-and-burn agricultural system in the Atlantic forest region of Rio de Janeiro. Cropped fields had significantly reduced soil aggregation indices and organic carbon contents, as well as increased impacts on their soil bacterial community structure, relative to forest fragments. The results demonstrate the applicability of the soil quality analytical framework proposed, and reveal that traditional shifting cultivation practices in the area studied are compatible with conservation of soil quality, provided that the fallow plots are maintained for periods longer than 5 years.

Little attention has been paid to the accumulation of soil organic matter (SOM) in the fringes of the mid-latitude desert. In this paper, soil samples from a long-term field experiment conducted from 1990 to 2013 at a research station in Urumqi, China by different fertilizer treatments, were used to determine soil properties and soil dissolved organic matter (DOM) by chemical analysis, fluorescence excitation emission matrix (EEM) spectroscopy, and high resolution-transmission electron microscopy (HR-TEM). The binding features of DOM under the addition of Ca(2+) were analyzed using a two-dimensional (2D) Fourier transform infrared (FTIR) spectrometer further to explore the response of the DOM to increasing concentrations of Ca(2+). Long-term application of chemical fertilizers and goat manure increased soil organic carbon (SOC) by 1.34- and 1.86-fold, respectively, relative to the non-fertilized control (8.95 g.kg(-1)). Compared with the control, application of chemical fertilizers and manure significantly increased the concentrations of Ca, Mg, Si, humic and fulvic acid-like substances in DOM but decreased the amounts of trivalent metals (Al and Fe) and protein-like substances. Although crystalline Al/Fe nanoparticles and amorphous or short-range-order Si/Al nanoparticles existed in all DOM samples, crystalline Ca/Si nanoparticles were predominant in the samples treated with goat manure. Although organic matter and Si-O-containing nanoparticles were involved in the binding of Ca(2+) to DOM, application of chemical fertilizers weakened Ca(2+) association with components of the amide II group (1510 cm(-1)) and Si-O linkage (1080 cm(-1)), whereas application of goat manure enhanced the affinity of Ca(2+) for Si-O linkage. Our results suggested that the enrichment of Ca in gray desert soil possibly helps accumulate SOM by forming crystalline Ca/Si nanoparticles in addition to Ca(2+) and organic matter complexes.

Soil erosion throughout Queensland's sugar cane producing lands emerged as a significant problem in the 1930s. Poor farming techniques such as leaving fallow land or fields with young crops bare during the wetter summer months and cultivating sloping land were blamed for this environmental problem. Drawing upon archival documents, government reports and published accounts of agricultural scientists, this paper aims to document how officers of the Queensland Bureau of Sugar Experiment Stations and the Soil Conservation Branch of the Queensland Department of Agriculture and Stock (later Primary Industries) tried developing soil conservation methods suited to land cropped with sugar cane. The conclusion from the historical analysis is that many Queensland canegrowers before 1980 were very slow to adopt the soil conservation methods advocated by the agricultural scientists, even though they acknowledged that soil erosion was a problem. This reluctance to 'save the land' changed during the 1980s following the emergence of an agricultural practice known as trash blanketing. The ease of its implementation and associated reduction in tillage costs contributed to its rapid uptake.

PurposeThe present study aims to determine the residue levels in the soil and water prior to, and after fertilization, as previous soil investigations in Kuwait indicated that different types of fertilizers are used leaving residues in the soil, in order to assist the prospective farmers in choosing environmental sound chemicals for each crop. The importance of the following is to determine the geologic conditions of the soil in such a productive farm area and the effect of the use of fertilizers.Design/methodology/approachTo achieve the study purpose soil and water samples were collected over a wide area and chemical parameters (pH, electrical conductivity (ECe), cations (Ca+2, Mg+2), and anions (CO3−2,HCO3−,Cl−)) were obtained via the suitable and most appropriate chemical analyses.FindingsThe soils have several levels of calcareous contents along with varying salinity and alkalinity. Before fertilization on average, soil ECe ranges from 0.93 to 4.37 mS/cm, pH from 7.4 to 7.60, cations 8.00 to 36.00 meq/l, and anions from 4.85 to 29.61 meq/l. After fertilization pH ranges from 7.09 to 7.47, ECe ranged from 3.79 to 12.85 mS/cm, cations ranges from 29.75 to 66.36 meq/l, and anions ranges from 15.18 to 63.32 meq/l; showing that ECe, cations and anions average values has increased by almost three to four orders of magnitude. Furthermore, ECe, pH, cations, and anions values have sharply increased with depth. The evidence from this study shows that vertical leaching adversely contributes to the deterioration of the groundwater quality and rate.Practical implicationsThe output of this study is intended to be the building block or the nuclei for a data bank on the prevailed agricultural practices in different aspects, and upon which further studies on the southern area of Kuwait will depend.Originality/valueThe farm areas in the southern region of Kuwait state (case study: Al‐Wafrah farms) suffer from misuse and mismanagement of the agricultural lands in different aspects. This paper provides new source of information on the historical record of farm development and the nature, performance and results of the associated agricultural practices in such areas, as so to be the base or the starting point form which further studies can go forth.

The field-scale application of apparent soil electrical conductivity (EC"a) to agriculture has its origin in the measurement of soil salinity, which is an arid-zone problem associated with irrigated agricultural land and with areas having shallow water tables. Apparent soil electrical conductivity is influenced by a combination of physico-chemical properties including soluble salts, clay content and mineralogy, soil water content, bulk density, organic matter, and soil temperature; consequently, measurements of EC"a have been used at field scales to map the spatial variation of several edaphic properties: soil salinity, clay content or depth to clay-rich layers, soil water content, the depth of flood deposited sands, and organic matter. In addition, EC"a has been used at field scales to determine a variety of anthropogenic properties: leaching fraction, irrigation and drainage patterns, and compaction patterns due to farm machinery. Since its early agricultural use as a means of measuring soil salinity, the agricultural application of EC"a has evolved into a widely accepted means of establishing the spatial variability of several soil physico-chemical properties that influence the EC"a measurement. Apparent soil electrical conductivity is a quick, reliable, easy-to-take soil measurement that often, but not always, relates to crop yield. For these reasons, the measurement of EC"a is among the most frequently used tools in precision agriculture research for the spatio-temporal characterization of edaphic and anthropogenic properties that influence crop yield. It is the objective of this paper to provide a review of the development and use of EC"a measurements for agricultural purposes, particularly from a perspective of precision agriculture applications. Background information is presented to provide the reader with (i) an understanding of the basic theories and principles of the EC"a measurement, (ii) an overview of various EC"a measurement techniques, (iii) applications of EC"a measurements in agriculture, particularly site-specific crop management, (iv) guidelines for conducting an EC"a survey, and (v) current trends and future developments in the application of EC"a to precision agriculture. Unquestionably, EC"a is an invaluable agricultural tool that provides spatial information for soil quality assessment and precision agriculture applications including the delineation of site-specific management units. Technologies such as geo-referenced EC"a measurement techniques have brought precision agriculture from a 1980's concept to a promising tool for achieving sustainable agriculture.

9 pages, 5 tables, 1 figure, 22 references. Consejo Superior de Investigaciones Científicas (CSIC), Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS), Sevilla, Spain., Soil quality evaluation is the process of predicting the capacity of a soil to function. Due to the many possible soil functions, simple measuring of an individual soil parameter is not sufficient. These soil-quality parameters or indicators are grouped in physical, chemical and biological components. Land evaluation, which tries to predict land behaviour for each particular use, is not the same as soil-quality assessment, basically because the biological parameters of the soil are not considered by land evaluation. However, the process of evaluating soil is not new, and agro-ecological land evaluation has much to offer in this sense. A state-of-the-art review of soil quality evaluation and monitoring is presented in this paper, focusing on the possibilities of applying the accumulated knowledge from past studies of land evaluation. An agro-ecological approach is suggested to facilitate the monumental task of relating the nearly infinite list of soil quality indicators to the numerous soil functions, such as an application of MicroLEIS DSS to soil quality., This work has been developed as a part of the activities from the ‘SCAPE: Soil Conservation and Protection for Europe’ EU Concerted Action, 2002–2005, funded by the DG-RTD, Energy, Environment and Sustainable Development Programme (Contract EVK2-CT2002-20016; coordinator Prof. A. C. Imeson)

The philosophy toward tillage throughout the last century in Hungary can be characterized as a fight against extreme climatic and economic situations. The ‘Hungarian reasonable tillage’ approach that was promoted by Cserhati at the end of the 1800s was aimed at reducing tillage without increasing the risk of crop failure in arable fields. Recently, new tillage trends and systems have been introduced because of the rise in energy prices and because of the need to cut production costs, conserve soil and water resources and protect the environment. In Hungarian relation, the rationalized plowing, loosening and mulching systems are counted to the new tillage solutions. There are new steps in the sowing methods too, such as seedbed preparation and plant in one pass, till and plant, mulch-till and plant and direct drilling, which are environment capable, throughout improving soil condition and avoiding the environment harms. The applicability of various soil conservation tillage methods is currently being tested in research projects and discussed in workshops throughout the country. In this paper, soil quality problems such as compaction, trends in soil tillage, and factors affecting soil quality or condition as well as improvement and maintenance are summarized. The data show that annual disking and plowing causes subsoil compaction at the depth of tillage within 3 years and that the compacted layer expanded both in surface and deeper layers after the 5th year. Soil quality deterioration by tillage-pans was improved by subsoiling and maintained by direct drilling and planting soil-loosening catch crops. Within a loam and a sandy loam soil there were close correlations between earthworm activity and soil quality. Earthworm numbers increased on undisturbed but noncompacted soils and soils that included stubble residues remaining on the surface, but did not increase on soils that were deteriorated by tillage-pans or left bare by the absence of mulch. Our goal for the new millennium, is to use only enough tillage to create and maintain harmony between soil conservation, soil quality and crop production.

Soils form the foundation for agriculture and are changed by farming through active management and unintentionally. Soil change from agriculture ranges from wholesale transformation to ephemeral and subtle modification. The archaeological record of early agricultural systems holds information about soil change on centurial to millennial scales, with important implications for long-term soil condition and land use sustainability. Knowledge of early agricultural management can also be inferred from soils, including farming strategies in dynamic, challenging environments. This paper discusses soil change processes and outcomes mainly using studies of ancient and traditional agriculture in arid regions of the Americas. The potential and limitations of soil change research methods in ancient agriculture are also considered. Soil anthropogenic change involves complex and interactive physical, chemical, and biological processes across a wide range of spatial and time scales. Soil change outcomes in early agriculture relating to soil health and productivity vary from improvement to degradation. Soil productivity improvement commonly resulting from management includes soil-landscape physical stabilization for crops, increased topsoil thickness and plant-available water capacity, and improved soil tilth and fertility. Degradation commonly results from unintentional soil-geomorphic-ecosystem changes that cause accelerated erosion, destabilization of soil structure and compaction, and decreases in plant nutrients and soil fertility. Soil change outcomes vary across space and time in response to complex environmental, agricultural, and social factors.

This paper describes the technical development and accuracy assessment of the most recent and improved version of the SoilGrids system at 250m resolution (June 2016 update). SoilGrids provides global predictions for standard numeric soil properties (organic carbon, bulk density, Cation Exchange Capacity (CEC), pH, soil texture fractions and coarse fragments) at seven standard depths (0, 5, 15, 30, 60, 100 and 200 cm), in addition to predictions of depth to bedrock and distribution of soil classes based on the World Reference Base (WRB) and USDA classification systems (ca. 280 raster layers in total). Predictions were based on ca. 150,000 soil profiles used for training and a stack of 158 remote sensing-based soil covariates (primarily derived from MODIS land products, SRTM DEM derivatives, climatic images and global landform and lithology maps), which were used to fit an ensemble of machine learning methods D random forest and gradient boosting and/or multinomial logistic regression D as implemented in the R packages ranger, xgboost, nnet and caret. The results of 10 -fold cross-validation show that the ensemble models explain between 56% (coarse fragments) and 83% (pH) of variation with an overall average of 61%. Improvements in the relative accuracy considering the amount of variation explained, in comparison to the previous version of SoilGrids at 1 km spatial resolution, range from 60 to 230%. Improvements can be attributed to: (1) the use of machine learning instead of linear regression, (2) to considerable investments in preparing finer resolution covariate layers and (3) to insertion of additional soil profiles. Further development of SoilGrids could include refinement of methods to incorporate input uncertainties and derivation of posterior probability distributions (per pixel), and further automation of spatial modeling so that soil maps can be generated for potentially hundreds of soil variables. Another area of future research is the development of methods for multiscale merging of SoilGrids predictions with local and/or national gridded soil products (e.g. up to 50 m spatial resolution) so that increasingly more accurate, complete and consistent global soil information can be produced. SoilGrids are available under the Open Data Base License.

The management of the fertilization in integrated production intends to produce good yields and high product quality, while protecting the soil from different processes such as erosion, salinization, and acidification. Principally, it seeks to maintain and improve soil fertility by preventing loss of organic matter and nutrient imbalances, while also preventing surface and groundwater pollution, and the main objective being to produce food of maximum nutritional value. In this paper we assess, in prevailing soil types in central Spain (Cambisol and Regosol), several limiting factors of soil fertility, such as soil compaction due to conservative tillage systems and climatic conditions which influence the vegetation and soil conditions (mainly during the summer). The analysis of integrated fertilization allows us to highlight the importance of maximizing resources and natural production mechanisms. We evaluate the nutritional requirements of crops, aiming to ensure long-term sustainable compatible agriculture which satisfies both the demands of society (concerning environmental protection) and the agricultural productivity requirements. In this context, the official guidelines in Spain have been to meet the standards and requirements established in integrated management programs. © 2014 Taylor & Francis.

Chlorophyll a fluorescence gives information about the plant physiological status due to its coupling to the photosynthetic electron transfer chain and to the further biochemical processes. Environmental stresses, which acts synergistically, disturbs the photosynthesis. The OJIP test, elaborated by Strasser and co-workers, enables comparison of the physiological status of plants grown on polluted vs. control areas. The paper shows that the Chl a measurements are very useful tool in evaluating of heavy metal ions influence on perennial grasses, tested as potential phytoremediators. Among 5 cultivars tested, the highest concentration of Cd and Zn ions, not associated with the yield reduction, was detected in the biomass of tall fescue cv. Rahela. Chl a fluorescence interpreted as double normalized curves pointed out Rahela as the outstanding cultivar under the HM ions stress.

International audience; The addition of pyrogenic carbon (C) in the soil is considered a potential strategy to achieve direct C sequestration and potential reduction of non-CO2 greenhouse gas emissions. In this paper, we investigated the long term effects of charcoal addition on C sequestration and soil physico-chemical properties by studying a series of abandoned charcoal hearths in the Eastern Alps of Italy established in the XIX century. This natural setting can be seen as an analogue of a deliberate experiment with replications. Carbon sequestration was assessed indirectly by comparing the amount of pyrogenic C present in the hearths (23.3+/-4.7 kg C m(-2)) with the estimated amount of charcoal that was left on the soil after the carbonization (29.3+/-5.1 kg C m(-2)). After taking into account uncertainty associated with parameters' estimation, we were able to conclude that 80+/-21% of the C originally added to the soil via charcoal can still be found there and that charcoal has an overall Mean Residence Time of 650+/-139 years, thus supporting the view that charcoal incorporation is an effective way to sequester atmospheric CO2. We also observed an overall change in the physical properties (hydrophobicity and bulk density) of charcoal hearth soils and an accumulation of nutrients compared to the adjacent soil without charcoal. We caution, however, that our site-specific results should not be generalized without further study.