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Soil water conservation in dryland agriculture mainly depends on precipitation. We chose 35 long‐term experiments and analysed the data by using meta‐analysis to check how fallow management methods affect soil water storage of dryland winter wheat planting (SWS), precipitation storage efficiency (PSE), crop yield and water use efficiency (WUE). No‐tillage (NT), compared to conventional tillage (CT) in the fallow period, increased PSE, SWS, grain yield and WUE by 32.9%, 27.1%, 30.5% and 22.6%, respectively. Reduced tillage (RT) and subsoil tillage (ST) increased PSE by 15.2% and 11.7%, SWS by 17.4% and 15.0% and grain yield by 15.5 and 13.8%, respectively, but these had a non‐significant effect on WUE. The conservation tillage methods interacted significantly with the residue management and fallow mulching practices. Compared to CT, the conservation tillage methods with fallow mulching increased PSE, SWS, grain yield and WUE, but the growing of cover crops (designated as biological mulching) decreased PSE, SWS and grain yield by 17.3%, 13.0% and 32.0%, and had a non‐significant impact on WUE. Under the condition of straw mulching, NT increased PSE, SWS, grain yield and WUE by 43.7%, 38.1%, 40.6% and 42.9%, respectively, compared to CT. NT and RT increased the PSE, SWS and WUE, under normal mean annual precipitation (MAP), however, ST increased these observations under wet MAP, compared to CT. The effects of tillage methods varied with soil texture, and they were highly interrelated with water conservation, wheat yield and water use. We conclude that compared to conventional tillage, the conservation tillage methods increased soil water conservation during the fallow period, which increased wheat yield and water use. Moreover, NT with or without residue retention increased the fallow water conservation and wheat yield. Crop residues should be retained while applying RT and ST to grow winter wheat in dryland regions. [ABSTRACT FROM AUTHOR]

Integrated watershed management plays a vital role in promoting sustainable water resource management and addressing environmental challenges. This study aims to analyze and assess the effectiveness of existing IWM practices and develop new strategies to improve watershed management. The data collection process encompassed comprehensive field observations, surveys, and consultations with the stakeholders. According to a hydrometer test, loam soil was the average dominant soil type in Elgo and Kola shell kebele. The assessment of existing soil water conservation initiatives adhered to the rigorous standards set by the Ministry of Agriculture. From 2016 to 2022, Elgo Kebele saw significant land use changes: agriculture expanded by 11.24 %, bare land by 2.05 %, water bodies by 1.79 %, and settlements by 0.54 %, while forests declined by 15.34 %. In Kola Shele, agriculture, water bodies, and settlements slightly increased by 0.5 %, 1.03 %, and 0.033 %, respectively, with decreases in bare land (1.82 %) and forest (0.05 %). Only 25 % of sampled plots met the criteria for effective soil water conservation systems, indicating challenges in current practices. For cultivated land with less than a 15 % slope and vertisol, recommended conservation practices include broad bed and furrow, conservation tillage, grass strips, grassland improvement, and mulching. For slopes greater than 50 %, hillside terracing, graded bunds, and trenches are advised. Additional measures, such as water harvesting, grass waterways, revegetation, and actions against illegal farming, were proposed. In summary, this study highlights the urgent need for improved IWM practices, and used to enhance watershed management, address environmental and socio-economic issues, and promote sustainable land use in the study.

ABSTRACTSoil erosion and subsequent land degradation undermine efforts to ensure food security and environmental sustainability in Ethiopia. The government of Ethiopia has implemented extensive soil and water conservation (SWC) programs in severely degraded and food-insecure areas of the country, in some cases integrated with subsequent or parallel irrigation development. However, the effectiveness of these interventions has not been extensively evaluated. This study, therefore, evaluates the performance and impacts of SWC practices in terms of improving vegetation greenness and reducing soil erosion in Feresmay watershed in Ethiopia. Long-term Landsat-based Normalised Difference Vegetation Index (NDVI), Revised Universal Soil Loss Equation (RUSLE), and Soil and Water Assessment Tool (SWAT) were used for change-detection analysis before and after the implementation of various SWC interventions. The results revealed the positive impacts of SWC interventions in improving the vegetation greenness and soil erosion reduction although the outcome varied by intervention. Increased vegetation greenness was observed largely in areas where area closure with catchment treatment (ACCT) and impacts of irrigation (IRR) interventions are dominant, while relatively little impact was observed at the watershed level analysis. Although these interventions helped to reduce soil loss, the results highlighted the need for more SWC interventions to minimise further soil loss.

Winter wheat monoculture is a predominant cropping system for agricultural production in dry areas. However, fallow management effects on soil water conservation and crop yield and water use have been inconsistent among studies. We selected 137 studies and performed a meta-analysis to test the effects of tillage and mulching during the fallow period on precipitation storage efficiency (PSE), soil water storage at wheat planting (SWSp), crop yield, evapotranspiration (ET), and water use efficiency (WUE). Compared to conventional tillage (CT), conservation tillage during fallow period overall increased PSE, SWSp and wheat yield by 31.0, 6.4, and 7.9%, respectively, but did not affect ET and WUE. No tillage (NT) had a better performance on soil water conservation during fallow period but a similar effect on wheat yield and WUE compared to reduced tillage (RT) and subsoil tillage (ST). Compared to no mulching, fallow mulching practices overall increased PSE by 19.4%, but had a non-significant impact on SWSp, wheat yield, and ET. Compared to straw mulching, film mulching, and stubble mulching during fallow period, cover cropping as a biological mulching decreased SWSp, wheat yield, and WUE significantly. Wheat WUE was improved by straw mulching but not affected by film mulching and stubble mulching. Strong interactions between tillage method and mulching practices were found for most variables. NT with fallow mulching or with no mulching exhibited a greater impact on soil water conservation during fallow period compared to other combinations. The effects of tillage and mulching during fallow period on soil water conservation and wheat yield and water use also varied with soil and climatic conditions. Overall, NT in combination with straw mulching significantly increased SWSp, PSE, wheat yield, and WUE and can be the best fallow management practice for winter wheat production in varying edaphic and climatic conditions. [ABSTRACT FROM AUTHOR]

Soil erosion and subsequent land degradation undermine efforts to ensure food security and environmental sustainability in Ethiopia. The government of Ethiopia has implemented extensive soil and water conservation (SWC) programs in severely degraded and food-insecure areas of the country, in some cases integrated with subsequent or parallel irrigation development. However, the effectiveness of these interventions has not been extensively evaluated. This study, therefore, evaluates the performance and impacts of SWC practices in terms of improving vegetation greenness and reducing soil erosion in Feresmay watershed in Ethiopia. Long- term Landsat-based Normalised Difference Vegetation Index (NDVI), Revised Universal Soil Loss Equation (RUSLE), and Soil and Water Assessment Tool (SWAT) were used for change-detection analysis before and after the implementation of various SWC interventions. The results revealed the positive impacts of SWC interventions in improving the vegetation greenness and soil erosion reduction although the outcome varied by intervention. Increased vegetation green-ness was observed largely in areas where area closure with catchment treatment (ACCT) and impacts of irrigation (IRR) interventions are dominant, while relatively little impact was observed at the watershed level analysis. Although these interventions helped to reduce soil loss, the results highlighted the need for more SWC interventions to minimise further soil loss. [ABSTRACT FROM AUTHOR]

Amplapura is located in the highlands having a potential area of green open land which can absorb rainwater freely into the ground. However, in recent times, land conversion has begun to develop with new housing buildings, Griya Galiran Regency Housing. Furthermore, the effectiveness of the land area is still able to absorb water and maintain groundwater balance. A rainwater harvesting plan (RH) is needed, or, more popularly, rainwater harvesting. In this area. The aim is to provide a portion of residential land space for rainwater infiltration into the pores or soil cavities using the infiltration well method. The results showed that the Griya Galiran Regency Housing had an acceptable sand soil type and absorbed soil quickly, with a soil permeability coefficient (k) of 0.0014 cm/s. Designing the dimensions of the infiltration well at the Griya Galiran Regency Housing with an area of 70 m2 based on SNI 03-2453-2002 for a circular cross-section, an infiltration well with a diameter of 1.2 m with a depth of 2 m is made. In contrast, as a rectangular cross-section, an infiltration well has a side length of 1 m with a depth of 2 m.

Winter wheat monoculture is a predominant cropping system for agricultural production in dry areas. However, fallow management effects on soil water conservation and crop yield and water use have been inconsistent among studies. We selected 137 studies and performed a meta-analysis to test the effects of tillage and mulching during the fallow period on precipitation storage efficiency (PSE), soil water storage at wheat planting (SWSp), crop yield, evapotranspiration (ET), and water use efficiency (WUE). Compared to conventional tillage (CT), conservation tillage during fallow period overall increased PSE, SWSp and wheat yield by 31.0, 6.4, and 7.9%, respectively, but did not affect ET and WUE. No tillage (NT) had a better performance on soil water conservation during fallow period but a similar effect on wheat yield and WUE compared to reduced tillage (RT) and subsoil tillage (ST). Compared to no mulching, fallow mulching practices overall increased PSE by 19.4%, but had a non-significant impact on SWSp, wheat yield, and ET. Compared to straw mulching, film mulching, and stubble mulching during fallow period, cover cropping as a biological mulching decreased SWSp, wheat yield, and WUE significantly. Wheat WUE was improved by straw mulching but not affected by film mulching and stubble mulching. Strong interactions between tillage method and mulching practices were found for most variables. NT with fallow mulching or with no mulching exhibited a greater impact on soil water conservation during fallow period compared to other combinations. The effects of tillage and mulching during fallow period on soil water conservation and wheat yield and water use also varied with soil and climatic conditions. Overall, NT in combination with straw mulching significantly increased SWSp, PSE, wheat yield, and WUE and can be the best fallow management practice for winter wheat production in varying edaphic and climatic conditions. [ABSTRACT FROM AUTHOR]

Water shortage is a serious threat to agriculture production in the North China Plain. Sustainable management practices can improve the water use efficiency of winter wheat, but currently no academic consensus has been reached. Therefore, we performed a meta-analysis that included 2194 observations from 209 articles to assess the water use efficiency of wheat in this area. The groundwater provides for 34%–37% of wheat evapotranspiration, which increases the decline of groundwater levels. The management of wheat irrigation appears to be the key process in improving agricultural water use efficiency. We observed from regression analyses that the factors such as climate, soil, and management significantly affect the water use efficiency of wheat (p < 0.05). The data showed that nitrogen input and irrigation significantly increased wheat yields (p < 0.05), but irrigation did not significantly improve the water use efficiency compared to rain-fed wheat. The optimal water use efficiency was obtained when the irrigation amount was 80–160 mm, or irrigation was applied twice, or the seasonal irrigation amount plus precipitation was ≤ 240 mm. In contrast, a nitrogen input significantly increased evapotranspiration and water use efficiency. The water use efficiency improvement was especially prominent when the nitrogen application rate was 220–250 kg·ha−1. Moreover, subsoiling and straw return should be recommended for increasing yield, reducing evapotranspiration, and improving water use efficiency. These practices can ultimately save over 240 mm of water and 75 kg·ha−1 of nitrogen, which contributes to a sustainable agricultural development. Here, we demonstrate for the first time the impact of management practices on crop water use efficiency at a regional scale and propose a sustainable agricultural development scheme. [ABSTRACT FROM AUTHOR]

Winter wheat monoculture is a predominant cropping system for agricultural production in dry areas. However, fallow management effects on soil water conservation and crop yield and water use have been inconsistent among studies. We selected 137 studies and performed a meta-analysis to test the effects of tillage and mulching during the fallow period on precipitation storage efficiency (PSE), soil water storage at wheat planting (SWSp), crop yield, evapotranspiration (ET), and water use efficiency (WUE). Compared to conventional tillage (CT), conservation tillage during fallow period overall increased PSE, SWSp and wheat yield by 31.0, 6.4, and 7.9%, respectively, but did not affect ET and WUE. No tillage (NT) had a better performance on soil water conservation during fallow period but a similar effect on wheat yield and WUE compared to reduced tillage (RT) and subsoil tillage (ST). Compared to no mulching, fallow mulching practices overall increased PSE by 19.4%, but had a non-significant impact on SWSp, wheat yield, and ET. Compared to straw mulching, film mulching, and stubble mulching during fallow period, cover cropping as a biological mulching decreased SWSp, wheat yield, and WUE significantly. Wheat WUE was improved by straw mulching but not affected by film mulching and stubble mulching. Strong interactions between tillage method and mulching practices were found for most variables. NT with fallow mulching or with no mulching exhibited a greater impact on soil water conservation during fallow period compared to other combinations. The effects of tillage and mulching during fallow period on soil water conservation and wheat yield and water use also varied with soil and climatic conditions. Overall, NT in combination with straw mulching significantly increased SWSp, PSE, wheat yield, and WUE and can be the best fallow management practice for winter wheat production in varying edaphic and climatic conditions.

Maize production in Asia is rapidly increasing. For its sustainable production, the effects of raw and dry manure application on soil water dynamics, nutrient leaching, and plant growth were investigated. Nitrogen (N) and phosphorus (P) concentrations in the percolated water below a 110-cm depth of field-lysimeter columns were analyzed to quantify leaching. Soil water, soil temperature, and plant growth were routinely monitored. The manure application practices increased soil water content by 0.008-0.025 cm³ cm-3 throughout the vegetative period by reducing bulk density and reduced the daytime temperature range by 0.4-1.2°C. The average leaching concentrations of total N increased from 2.6 to 4.7 mg N L-1 and available P decreased from 0.12 to 0.04 mg P L-1 between 63 and 93 DAS (day after sowing), respectively. The manure treatments did not increase nutrient leaching load at 63 DAS, but at 93 DAS the N load was increased by 219-324 g ha-1 and P load by 2.0-3.1 g ha-1 compared with the control treatment. The dry manure released a larger amount of N (30.7%) and P (3.2%) in the leachates than the raw manure. The dry and raw manure treatment produced 14.5 and 5 cm taller plants, respectively than the control treatment. Manure application with a slight modification in nutrient management can avoid the nutrient leaching problem. [ABSTRACT FROM AUTHOR]

Poor soil fertility status due to erosion, intensive farming, and leaching of nutrients causes food insecurity in Ethiopia. Hence, estimating soil fertility status using different measurements is very essential to secure food insecurity. The aim of this study was to determine the effects of land management on soil fertility using a nutrient balance approach at Kecha and Laguna micro watersheds in 2016. Plant nutrient losses were estimated through measuring discharge and sediment loads coming from the treated (Kecha) and untreated (Laguna) catchments. A total of 40 bulk sediment and water samples were collected on a monthly basis. The inputs used in the two catchments, inorganic fertilizer and organic manure, were quantified through interviews using a semi-structured questionnaire. Plant samples were collected from 92 plots for determining grain yield (OUT1) and straw biomass (OUT2). Other inputs and outputs were calculated using a transfer function. From sediment, grain and straw samples, NPK contents were determined. The nutrient balances were found to be −89.37, −23.66 and −124.75 NPK kg/ha, and −112.41, −20.62 and −130.26 NPK for Kecha and Laguna, respectively. The main paths for these negative balances were residue removal and soil losses. Higher nutrient losses were observed in Laguna than Kecha watershed; this may be due to lack of soil management practices, crop rotation and planting of leguminous plants. Therefore, soil management practices should be done to reduce these higher losses of plant nutrients, and maintain crop residues in the farm so that nutrient recycling and better soil fertility can be achieved.

Constructing a silt pit is one of the most widely adopted and effective practices used in oil palm plantations to conserve soil and water. The objective of this study was to utilize the HYDRUS-2D/3D to determine the optimal dimensions of silt pit and optimise the simulation results employing the multiple linear regression (MLR) and/or artificial neural network (ANN). Both methods were used to select the optimal size and dimensions of silt pit sizes depending on the amount of rain and soil properties. The treatments that were adopted included: 1) seven soil textures, 2) five surface slopes, and 3) three silt pits sizes. Each silt pit size comprised of three depth levels to accommodate the amount of water available in the pit. The approach first utilised the HYDRUS-2D/3D software to simulate the time-to-empty (TTE) of various silt pit sizes on different soil and slopes. Secondly, trends were then distinguished from the data, and the best fit was determined using MLR and ANN models to estimate the optimal silt pit size. The TTE was affected by the water head in the pits (H), pit width (W), the amount of water applied (Vw), and the pit volume (Vp), but was not affected by the surface slope (Slope). The findings demonstrated that the MLR models did not perform sufficiently to represent the results of TTE (R² = 0.632; MSE = 85.83) compared with the ANN models (R² = 0.977; MSE = 10.33). This was mainly due to the non-linear relations of these factors. The results demonstrated that by using the same input data, the ANN models could favourably be used for TTE predictions. [ABSTRACT FROM AUTHOR]

Poor soil fertility status due to erosion, intensive farming, and leaching of nutrients causes food insecurity in Ethiopia. Hence, estimating soil fertility status using different measurements is very essential to secure food insecurity. The aim of this study was to determine the effects of land management on soil fertility using a nutrient balance approach at Kecha and Laguna micro watersheds in 2016. Plant nutrient losses were estimated through measuring discharge and sediment loads coming from the treated (Kecha) and untreated (Laguna) catchments. A total of 40 bulk sediment and water samples were collected on a monthly basis. The inputs used in the two catchments, inorganic fertilizer and organic manure, were quantified through interviews using a semi-structured questionnaire. Plant samples were collected from 92 plots for determining grain yield (OUT1) and straw biomass (OUT2). Other inputs and outputs were calculated using a transfer function. From sediment, grain and straw samples, NPK contents were determined. The nutrient balances were found to be −89.37, −23.66 and −124.75 NPK kg/ha, and −112.41, −20.62 and −130.26 NPK for Kecha and Laguna, respectively. The main paths for these negative balances were residue removal and soil losses. Higher nutrient losses were observed in Laguna than Kecha watershed; this may be due to lack of soil management practices, crop rotation and planting of leguminous plants. Therefore, soil management practices should be done to reduce these higher losses of plant nutrients, and maintain crop residues in the farm so that nutrient recycling and better soil fertility can be achieved. [ABSTRACT FROM AUTHOR]

Progress in sensor technologies has allowed real-time monitoring of soil water. It is a challenge to model soil water content based on remote sensing data. Here, we retrieved and modeled surface soil moisture (SSM) at the U.S. Climate Reference Network (USCRN) stations using Sentinel-1 backscatter data from 2016 to 2018 and ancillary data. Empirical machine learning models were established between soil water content measured at the USCRN stations with Sentinel-1 data from 2016 to 2017, the National Land Cover Dataset, terrain parameters, and Polaris soil data, and were evaluated in 2018 at the same USCRN stations. The Cubist model performed better than the multiple linear regression (MLR) and Random Forest (RF) model (R2 = 0.68 and RMSE = 0.06 m3 m-3 for validation). The Cubist model performed best in Shrub/Scrub, followed by Herbaceous and Cultivated Crops but poorly in Hay/Pasture. The success of SSM retrieval was mostly attributed to soil properties, followed by Sentinel-1 backscatter data, terrain parameters, and land cover. The approach shows the potential for retrieving SSM using Sentinel-1 data in a combination of high-resolution ancillary data across the conterminous United States (CONUS). Future work is required to improve the model performance by including more SSM network measurements, assimilating Sentinel-1 data with other microwave, optical and thermal remote sensing products. There is also a need to improve the spatial resolution and accuracy of land surface parameter products (e.g., soil properties and terrain parameters) at the regional and global scales.

Erosional processes are highly affected by seasonal climatic fluctuations and soil management practices. Controlled grass cover is one of the most used soil conservation practices adopted in temperate climates, even if the protective effect of grass cover may decrease according to seasonal pattern. This technique is effective and, thus, widely adopted in the inter-rows of orchards such as olives, citrus or vineyards. This study reports the erosive events recorded in two different rain-fed hillslope vineyards with different rows orientation located in the Monferrato region, NW Italy. The study is addressed at compare the effects of different inter-row managements and rainfall characteristics on runoff and soil loss in hillslope vineyards (average slope from 15% to 35%). Rainfall, runoff and erosion variables were monitored in hydraulically bounded vineyard plots, where the inter-rows were managed with tillage and grass cover. Seventy-two erosive events were recorded in the period 1992–1996 in two vineyard plots with rows along the contour lines while 86 erosive events were recorded in two plots with rows up-and-down the slope from 2000 to 2014 (158 erosive events and four plots in total). Events were classified according to rainfall characteristics as “long-lasting”, “intense” and “normal”. In plots with rows along the contour lines, “intense” events were responsible for the highest mean soil loss in tilled plots (0.7 Mg ha −1 ) with very high erosion rates (12.3 Mg ha −1 ) observed during a single storm. In plots with rows up-and-down the slope the highest erosion rates, 21.2 and 3.4 Mg ha −1 , were recorded during fall “long-lasting” events in the tilled and grass cover plots respectively. The grass cover proved to be effective in decreasing runoff and soil losses during most of the events (at least 68% and 61% of the occurrences, respectively) reducing soil losses especially during summer storms when most of the “intense” events occured. Furthermore, the results show the fundamental role of contour-slope row orientation in reducing runoff and soil losses, disregarding the inter-rows soil management that is adopted. [ABSTRACT FROM AUTHOR]

Highlights • Necessity to test the soil for essential nutrients and balance soil pH prior to applying soil conditioners for increasing water holder capacity. • To estimate a valid irrigation demand, include evapotranspiration (ETo) and rainfall as part of the selection of an irrigation rate standard. • Before programming irrigation system controllers, all associated hydraulic building parameters must be audited and verified. • Irrigation controllers should be compatible with Building Management Systems to ensure accuracy of water supply records UAE water recycling quality standards should include nutrient parameters limits because these have an impact on soil water holding capacity. Abstract The purpose of this research is to investigate the application of three different soil additives on existing selected draught resistant plants in 2016 and 2017 and how these can help improve soil conditions and the reduction of desalinated water for landscape irrigation in the UAE. The methodology of this Doctorate in Sustainable Built Environment (D.SBE) action research project, designed, developed and implemented by the first author, uses a mixed method. The case study is a 364 beds hospital located in Abu Dhabi, capital city of the UAE, with a vegetated open space and decorative water features representing more than 50% of the building footprint. The primary source of the medical facility landscape irrigation and water feature is designed to be air conditioning condensate water to avoid usage of any desalinated water in an arid environment. For four months of the year, the irrigation demand will not be met by the condensate water in winter because peak condensate formation occurs in summer. This shortfall availability during the winter months is proposed to be met by soil amendment and by use of other alternative water types. The soil test results show rapid plant growth with one of the soil conditioner solution whereas water savings is inconclusive due to irrigation system hydraulic irregularities and the lack of irrigation standardized rating for building operation. The next steps are to firstly balance the soil pH with a gypsum solution, to secondly reprogram the irrigation system controller with tested and audited hydraulic building parameters and to thirdly include all adequate parameters including ET o and rainfall to estimate the irrigation demand so that water savings can be accurately monitored. This intervention study will help understand the correlation between soil water quality together with irrigation rate and irrigation distribution system’s audit and how these factors impact on the environment, operation and maintenance cost and practices, greenhouse gas emissions, and building systems water and energy consumption. The results may be relevant to local authorities responsible for making and adjusting standards for outdoor irrigation strategy for all types of building. [ABSTRACT FROM AUTHOR]

Straw mulching is widely used to conserve soil water and increase crop yields. The effects of wheat straw mulching rate and method on dryland soil water storage, winter wheat ( Triticum aestivum L.) growth and yield, and water-use efficiency (WUE) were examined from 2008 to 2015 in the Loess Plateau of China. Treatments included wheat straw mulching at a high rate of 9000 kg ha −1 (HSM) and low rate of 4500 kg ha −1 (LSM) throughout the year, straw mulching at a rate of 9000 kg ha −1 during summer fallow (FSM), and no mulching (CK). Soil water storage at wheat planting and precipitation-storage efficiency (PSE) were greater with straw mulching than without. Soil water storage at harvest was greater with HSM than CK and FSM. Wheat yield components such as number of wheat seedling, plant, tiller, and spike and thousand-grain weight varied with treatments and years, but wheat aboveground biomass and grain yields were usually greater with mulching than without during years with below-average precipitation. Harvest index and WUE were lower with LSM and HSM than other treatments in most years, but evapotranspiration did not vary with treatments. Overall, the increased PSE due to straw mulching did not increase yield and WUE, and straw mulching could sustain dryland wheat grain yield only in dry years. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In arid and semiarid regions of northern China, there is an increasing interest in using water-saving superabsorbent polymer (SAP) for field crop production. Experiments were conducted during 2009 and 2010 to study the growth and yield characteristics of summer corn (Zea mays L.) under different (control, 0; low, 10; medium, 20; high, 30 and very high, 40 kg/ha) rates of SAP in a drought-affected field of northern China. Corn yield increased slightly following SAP application at low and medium rate, but significantly at high and very high rates by 22.4 and 27.8%. At the same time, plant height, stem diameter, leaf area, biomass accumulation, harvest index and relative water content as well as protein, sugar and starch contents in the grain increased significantly following SAP treatments. The optimum application of superabsorbent polymer for corn cultivation in the study area would be 30 kg/ha as it best increased the grain yield and quality and maintained higher levels of soil nutrients. Lower rates (10 and20 kg/ha) or higher (≥ 40 kg/ha) rates would neither be sufficient nor economical. We suggest that the application of SAP at 30 kg/ha could be an efficient and economic soil management practice for summer corn production in the drought affected regions of northern China or other areas with similar ecologies.

In comparison with incorporating wheat stubble, soil water storage in Vertisols is believed to be enhanced by standing wheat stubble. It is widely believed that a significant proportion of the enhanced water storage is attributable to reductions in soil evaporation. The objective of this study was to quantify the differences in fallow soil evaporation in a Vertisol under two cotton ( Gossypium hirsutum L.)-wheat ( Triticum aestivum L.) rotation systems where wheat stubble was either retained as an in situ mulch (standing stubble) or incorporated. Soil cores were extracted from the surface 70 mm of beds after the wheat phase of wheat stubble incorporated (post-incorporation) and standing wheat stubble plots in an ongoing cropping systems experiment near Narrabri, NSW during the 2008–09 and 2009–10 summer fallow periods. The cores were saturated, drained and subjected to drying cycles under two evaporation rates (4 and 6 mm d −1 ) during which evaporation was assessed by weighing the cores. Although cumulative evaporation was generally greater with wheat stubble incorporation than with standing stubble, the differences were small. These results suggest that the more effective water storage observed under the latter practice when rainfall was the major source of water may be not due to large reductions in evaporation but to enhanced infiltration. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Plant Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A comprehensive assessment of soil organic matter (SOM) dynamics in semi-arid agrosystems implementing soil and water conservation (SWC) measures is still lacking despite their extent, ecological and economic significance. Therefore, we assessed the long-term impact of a commonly used SWC technique (Fanya-juu terracing) on SOM-related properties in South Eastern Kenya. A soil sampling campaign was conducted in a replicated stratified random manner on three land uses that had been continuously managed for over 30 years. Samples were analyzed for organic carbon and nitrogen contents, δ 13 C, δ 15 N, pH and texture. Compared to sites implementing conventional agriculture, the establishment of SWC structures in this erosion-prone landscape resulted in the recovery of SOM levels comparable to those observed in neighboring semi-natural ecosystems. Sites under conventional agriculture practices contained 20 Mg C ha − 1 (0.85 m), while sites with SWC measures and those hosting semi-natural vegetation stored above a third more. There were significant differences in soil C/N ratios as well as in δ 13 C and δ 15 N values between SWC cultivation practices classified according to the presence or absence of trees. The presence of woody vegetation in sites with SWC structures had a strong impact on the spatial variability of SOM-related properties. There was also a significant negative relationship between δ 15 N values and C/N ratios across the different land uses. Our findings indicate the existence of contrasting SOM dynamics caused by vegetation-related effects, and provide suggestions for enhancing SOM storage in agricultural sites implementing SWC measures. [ABSTRACT FROM AUTHOR]

• Effects of mattic epipedon coverage on surface water conservation capacity were examined. • Declining mattic epipedon cover decreased surface runoff, especially under moderate rainfall. • Increased rainfall and mattic epipedon cover decreased evapotranspiration. • Soil water consumption aggravated with decreasing mattic epipedon coverage under non-rainfall. • Higher mattic epipedon cover maintains higher water conservation capacity under moderate rainfall. The Qinghai-Tibetan Plateau—known as the roof of the world and the water tower of Asia—is facing serious degradation of its ecosystems, with alpine meadows being particularly threatened. However, little is known about how the loss of mattic epipedon (the characteristic topsoil of alpine meadows) alters the water conservation capacity of the region. Here we examined the effects of different mattic epipedon coverages on surface runoff, evapotranspiration, and soil water storage under different rainfall conditions. Our results showed that the surface runoff was significantly higher under moderate rain conditions (P > 10 mm day−1) than under light rain conditions (P < 10 mm day−1), and that declining coverage significantly increased surface runoff, especially under moderate rain conditions. The average evapotranspiration at 90 %, 60 %, and 30 % mattic epipedon coverages were 5.38 mm, 5.88 mm, and 6.38 mm under non-rainfall conditions, and 0.97 mm, 1.60 mm, and 2.24 mm under moderate rain conditions. Meanwhile, mattic epipedon coverage had a positive effect on the supplementation of soil water under moderate rainfall and on the conservation of soil water under non-rainfall conditions. Overall, alpine meadows with higher mattic epipedon coverage were more effective at maintaining surface runoff and improving soil water conservation. These findings highlight the importance of conserving and restoring alpine meadows to improve the water security in the Qinghai-Tibetan Plateau and other downstream regions. [ABSTRACT FROM AUTHOR]

Silt pit is one of the recommended soil water conservation practices in oil palm plantations. It is commonly regarded that the larger and deeper the silt pit, the more effective the pit would be to conserve soil water. This hypothesis was tested in this paper, where the effectiveness of four silt pit dimensions on conserving soil water in the oil palm active rooting zone was simulated using the HYDRUS 2D model. These silt pits had different sizes and total wet wall-to-floor area ratio (W:F): H1 silt pit (1x1x1 m of width, length, and depth, respectively, and W:F ratio of 4.0), H2 (1.5x1x1 and W:F of 2.5), H3 (2x1x0.5 and W:F of 1.5) and H4 (2x1x2 and W:F of 1.5). Simulations showed that silt pits with larger W:F ratios could store water for longer periods and feed water to a farther horizontal distance within the soil compared to silt pits with smaller W:F ratios. HI took the longest to dry out, whereby it took 14 to 19 hours longer to dry out compared to than H2, H3 and H4. HI and H3 could feed water as far as 80 cm away from the pit more than H2 and H4 (60 and 50 cm, respectively). This is because silt pits with larger W:F ratios had larger horizontal water flow than the vertical water flow. Meanwhile, the depth of a silt pit should not be below the oil palm active rooting depth, which water would flow out of reach by the roots. This study is a preliminary work to a field experiment where simulations from this paper would be validated against measurements obtained in the field before recommending the use of silt pits and their size to be constructed in oil palm plantations. [ABSTRACT FROM AUTHOR]

Sorghum (Sorghum bicolor L.) is an important crop for production in dryland regions of the globe. Traits identified in many sorghum lines that apparently make them adapted for dryland conditions are restricted transpiration rate both early in the soil drying cycle and under high atmospheric vapour pressure deficit. It was hypothesised that these responses couldbearesultofdifferencesinhydraulicconductanceofthe plants:thosewith low hydraulic conductancewould be more likely toexpress restricted transpiration rates. The location of the lower hydraulic conductance in the plant could also be important with a low conductance in the leaf xylem to stomata pathway possibly being more advantageous than in the root. Inthis study, the amount and location of the hydraulic conductance was measured in 20 sorghum genotypes.Those genotypes that expressed an early decrease in transpiration rate with soil drying had greater plant and leaf hydraulic conductance than those genotypes that had the later decreases in transpiration rate, which was in contrast with what was hypothesised. However, sorghum genotypes that segregated between two groups based on expression of a maximum transpiration trait also segregated based on their hydraulic conductance. Those genotypes that expressed the maximum transpiration trait had lower hydraulic conductance for the intact plant and in the leaves. [ABSTRACT FROM AUTHOR]

Climate, hydrology and vegetation are closely linked at local, regional and global scales. The recent land use and plant production systems are adapted to the present climatic conditions. Thus, studies on the influence of possible climate change scenarios on the water and heat regimes of the soil-plant-atmosphere system are important in order to work out plant production strategies, adjusted to changed conditions. In this study the effect of two possible climate change scenarios on the soil water regime of a Chernozem soil was estimated for a Hungarian site. Soil water content dynamics simulated for different conventional and soil conserving soil tillage systems were evaluated, using the SWAP soil water balance simulation model. The combined effect of different soil tillage systems and climate scenarios was analysed. Climate scenarios were represented through the cumulative probability function of the annual precipitation sum. The SWAP model was calibrated against the measured in the representative soil profiles soil water content data. The site- and soil-specific parameters were set and kept constant during the scenario studies. According to the simulation results, increase in the average growing season temperature showed increase in climate induced soil drought sensitivity. The evaluated soil water content dynamics indicated more variable and less predictable soil water regime compared to the present climate. It was found that appropriate soil tillage systems that are combined with mulching and ensure soil loosening could reliably decrease water losses from the soil. From this aspect cultivator treatment created the most favourable for the plants soil conditions. It was concluded that soil conserving soil management systems, adapted to local conditions could contribute to soil moisture conservation and could increase the amount of plant available water under changing climatic conditions.

Abstract: In Central Aragon, winter cereal is sown in the autumn (November–December), commonly after a 16–18 months fallow period aimed at conserving soil water. This paper uses the Simple Soil–Plant–Atmosphere Transfer (SiSPAT) model, in conjunction with field data, to study the effect of long fallowing on the soil water balance under three tillage management systems (conventional tillage, CT; reduced tillage, RT; and no-tillage, NT). This was on the assumption that soil properties would remain unchanged during the entire fallow season. Once the model was validated with data obtained before primary tillage implementation, the differences between simulated and observed soil water losses for the CT and RT treatments could be interpreted as the direct effect of the soil tillage system. The model was calibrated and validated in a long-term tillage experiment using data from three contrasting long-fallow seasons over the period 1999–2002, where special attention was paid to predicting soil hydraulic properties in the pre-tillage conditions. The capacity of the model to simulate the soil water balance and its components over long fallowing was demonstrated. Both the fallow rainfall pattern and the tillage management system affected the soil water budget and components predicted by the model. The model predicted that about 81% of fallow seasonal rainfall is lost by evaporation in long-fallow periods with both a dry autumn in the first year of fallow and a rainfall above normal in spring. Whereas, when the fallow season is characterised by a wet autumn during the first year of fallow the model predicted a decrease in soil water evaporation and an increase in water storage and deep drainage components. In this case, the predicted water lost by evaporation was higher under NT (64%) than under RT (56%) and CT (44%). The comparison between measured and simulated soil water loss showed that the practice of tillage decreased soil water conservation in the short term. The long-term analysis of the soil water balance showed that, in fallow periods with a wet autumn during the first year of fallow, the soil water loss measured under CT and RT was moderately greater than that predicted by the model. [Copyright &y& Elsevier]

The impacts of climate change on soil water content and the resultant effects on agricultural productivity have raised a lot of concerns among cocoa farmers. This has rendered cocoa production a risky business. This makes soil water conservation practices crucial in cocoa production. Nonetheless, its adoption as a means to mitigate the adverse corollaries of climate change might be low in developing countries like Ghana. Our study focuses on soil water conservation practices carried out by cocoa farmers in Ghana to cope with climate change, its impact on productivity, and the determinants. We compiled primary data from 400 cocoa farmers. Due to potential inter-causal relationship between soil water conservation and productivity, we applied the three-stage least-squares and two-step Tobit with endogenous regressors. The study found that 97% of cocoa farmers carry out soil water conservation practices as a coping strategy for climate change. These are application of organic fertilizers, mulching, planting of leguminous crops, retention of trees, and planting of shade trees. On average, cocoa farmers carry out two of these practices. The study revealed that cocoa productivity is directly associated with soil water conservation practices. Additionally, the number of soil water conservation practices carried out by cocoa farmers increases with farm size, leasehold/individual land ownership, age of cocoa farm, income, farm management training, and government support. Also, cocoa productivity increases with income, association membership, farm management training, access to agricultural information, and soil fertility, but reduces with farm size. We delved deeper into the various soil water conservation practices adopted by cocoa farmers in Ghana to minimize the negative repercussions of climate change. The findings are relevant in understanding how cocoa farmers conserve soil moisture under the current climate dispensation as well as the inter-causal synergy between soil water conservation and cocoa productivity. We provide recommendations for policy- and decision-makers on soil water conservation practices to enhance productivity in the cocoa sector. These include organization of farm management training programmes by government, non-governmental organizations, and other stakeholders for cocoa farmers. Also, there is the need to support cocoa farmers with input subsidies and climate change information. [Display omitted] • Impacts of climate change on soil water make soil water conservation practices crucial in cocoa production. • We assessed the nexus between soil water conservation practices and climate change mitigation and impact on productivity. • The three-stage least-squares and two-step Tobit with endogenous regressors were used for the study. • Inter-causal synergy exist between soil water conservation and cocoa productivity. • Cocoa farmers adopt soil water conservation practices to mitigate climate change. [ABSTRACT FROM AUTHOR]

Progress in sensor technologies has allowed real-time monitoring of soil water. It is a challenge to model soil water content based on remote sensing data. Here, we retrieved and modeled surface soil moisture (SSM) at the U.S. Climate Reference Network (USCRN) stations using Sentinel-1 backscatter data from 2016 to 2018 and ancillary data. Empirical machine learning models were established between soil water content measured at the USCRN stations with Sentinel-1 data from 2016 to 2017, the National Land Cover Dataset, terrain parameters, and Polaris soil data, and were evaluated in 2018 at the same USCRN stations. The Cubist model performed better than the multiple linear regression (MLR) and Random Forest (RF) model (R2 = 0.68 and RMSE = 0.06 m3 m-3 for validation). The Cubist model performed best in Shrub/Scrub, followed by Herbaceous and Cultivated Crops but poorly in Hay/Pasture. The success of SSM retrieval was mostly attributed to soil properties, followed by Sentinel-1 backscatter data, terrain parameters, and land cover. The approach shows the potential for retrieving SSM using Sentinel-1 data in a combination of high-resolution ancillary data across the conterminous United States (CONUS). Future work is required to improve the model performance by including more SSM network measurements, assimilating Sentinel-1 data with other microwave, optical and thermal remote sensing products. There is also a need to improve the spatial resolution and accuracy of land surface parameter products (e.g., soil properties and terrain parameters) at the regional and global scales. [ABSTRACT FROM AUTHOR]

Soil erosion is affected by rainfall temporal patterns and intensity variability. In vineyards, machine traffic is implemented with particular intensity from late spring to harvest, and it is responsible for soil compaction, which likely affects soil hydraulic properties, runoff, and soil erosion. Additionally, the hydraulic and physical properties of soil are highly influenced by vineyards' inter-rows soil management. The effects on soil compaction and both hydrological and erosional processes of machine traffic were investigated on a sloping vineyard with different inter-row soil managements (tillage and permanent grass cover) in the Alto Monferrato area (Piedmont, NW Italy). During the investigation (November 2016–October 2018), soil water content, rainfall, runoff, and soil erosion were continuously monitored. Field-saturated hydraulic conductivity, soil penetration resistance, and bulk density were recorded periodically in portions of inter-rows affected and not affected by the machine traffic. Very different yearly precipitation characterized the observed period, leading to higher bulk density and lower infiltration rates in the wetter year, especially in the tilled vineyard, whereas soil penetration resistance was generally higher in the grassed plot and in drier conditions. In the wet year, management with grass cover considerably reduced runoff (−76%) and soil loss (−83%) compared to tillage and in the dry season. Those results highlight the need to limit the tractor traffic, in order to reduce negative effects due to soil compaction, especially in tilled inter-rows. [ABSTRACT FROM AUTHOR]

In tropical areas, a large number of natural forests have been transformed into other plantations, which affected the water conservation function of terrestrial ecosystems. In order to clari-fy the effects of land use changes on soil water conservation function, we selected four typical land use types in the central mountainous region of Hainan Island, i.e., natural forests with stand age greater than 100 years (VF), secondary forests with stand age of 10 years (SF), areca plantations with stand age of 12 years (AF) and rubber plantations with stand age of 35 years (RF). The effects of land use change on soil water holding capacity and water conservation (presented by soil water index, SWI) were assessed. The results showed that, compared with VF, the soil water holding capacity index of other land types decreased in the top soil layer (0-10 cm). AF had the lowest soil water holding capacity in all soil layers. Soil water content and maximum water holding capacity were significantly related to canopy density, soil organic matter and soil bulk density, which indicated that canopy density, soil organic matter and compactness were important factors influencing soil water holding capacity. Compared to VF, soil water conservation of SF, AF and RF were reduced by 27.7%, 54.3% and 11.5%, respectively. The change of soil water conservation was inconsistent in different soil layers. Vegetation canopy density, soil organic matter and soil bulk density explained 83.3% of the variance of soil water conservation. It was suggested that land use conversion had significantly altered soil water holding capacity and water conservation function. RF could keep the soil water better than AF in the research area. Increasing soil organic matter and reducing soil compaction would be helpful to improve soil water holding capacity and water conservation function in land management.