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Weedy rice (Oryza sativa f. spontanea) is a noxious weed infesting rice fields worldwide and causes great yield losses for cultivated rice. Effective management of this weed is essential for the world's rice production. Yet, the management of weedy rice is challenging. One of the reasons is that shattered weedy rice seeds stored in soil often trigger great weed proliferation in the succeeding crop seasons. To study the survival of weedy rice seeds in soil seedbanks, we conducted 90-day soil burial experiments at different soil depths from 0–25 cm, using weedy rice seeds from Jiangsu Province in China. Results from two independent experiments under the rice field and laboratory conditions indicated significant differences in seed death ratios (SDRs) and induced seed dormancy ratios (ISDRs) of weedy rice at different soil burial depths. Weedy rice seeds exposed to the soil surface (0 cm burial treatment) had the highest SDRs and lowest ISDRs. An evident pattern of quickly declining SDRs with increased soil burial depths was identified from this study, suggesting rapid losses of seed viability on the surface and in shallow layers of soil. Our findings provide a useful guide for designing strategies to effectively control weedy rice by maintaining shattered seeds on the surface or in shallow layers of soil. The practices can easily be achieved through adopting the no-till farming system, which can substantially minimize viable weedy rice seeds as an important component in comprehensive weed management strategies. [ABSTRACT FROM AUTHOR]

Onions are an important vegetable crop in Serra Gaúcha. However, adequate soil, nutrition, and disease management depend on harvest production and quality. Thus, using organic products as an alternative to conventional management methods has grown recently. This study aimed to evaluate the effect of different soil and phytosanitary management of organic origin on onion productivity. Three soil management methods were tested: soil without vegetation cover, soil with vegetation cover, and soil with vegetation cover plus Bokashi compost. The subplots corresponded to the weekly application of ginger extract, biweekly application of Bordeaux mixture, and control (water) for phytosanitary treatments. None of the phytosanitary treatments had any effect on the crop. Soil management influenced the severity of leet rust (Puccinia porri), where the use of straw and the concurrent application of straw and Bokashi reduced the severity. Straw and straw associated with Bokashi, although it produced plants with lower height and stem diameter, promoted greater bulb masses and productivity and increased soil fertility. Thus, the concomitant use of straw and Bokashi can be a strategy to increase onion productivity, which aligns with the principles of organic agriculture.

Weedy rice (Oryza sativa f. spontanea) is a noxious weed infesting rice fields worldwide and causes great yield losses for cultivated rice. Effective management of this weed is essential for the world’s rice production. Yet, the management of weedy rice is challenging. One of the reasons is that shattered weedy rice seeds stored in soil often trigger great weed proliferation in the succeeding crop seasons. To study the survival of weedy rice seeds in soil seedbanks, we conducted 90-day soil burial experiments at different soil depths from 0–25 cm, using weedy rice seeds from Jiangsu Province in China. Results from two independent experiments under the rice field and laboratory conditions indicated significant differences in seed death ratios (SDRs) and induced seed dormancy ratios (ISDRs) of weedy rice at different soil burial depths. Weedy rice seeds exposed to the soil surface (0 cm burial treatment) had the highest SDRs and lowest ISDRs. An evident pattern of quickly declining SDRs with increased soil burial depths was identified from this study, suggesting rapid losses of seed viability on the surface and in shallow layers of soil. Our findings provide a useful guide for designing strategies to effectively control weedy rice by maintaining shattered seeds on the surface or in shallow layers of soil. The practices can easily be achieved through adopting the no-till farming system, which can substantially minimize viable weedy rice seeds as an important component in comprehensive weed management strategies.

Background: The increasing demand for food production has led to a tenfold increase in nitrogen (N) fertilizer use since the Green Revolution. Nowadays, agricultural soils have been turned into high-nitrifying environments that increase N pollution. To decrease N losses, synthetic nitrification inhibitors (SNIs) such as 3,4-dimethylpyrazole phosphate (DMPP) have been developed. However, SNIs are not widely adopted by farmers due to their biologically limited stability and soil mobility. On the other hand, allelopathic substances from root exudates from crops such as sorghum are known for their activity as biological nitrification inhibitors (BNIs). These substances are released directly into the rhizosphere. Nevertheless, BNI exudation could be modified or even suppressed if crop development is affected. In this work, we compare the performance of biological (sorghum crop) and synthetic (DMPP) nitrification inhibitors in field conditions. Results: Sorghum crop BNIs and DMPP prevented an increase in the abundance of ammonia-oxidizing bacteria (AOB) without affecting the total bacterial abundance. Both nitrification inhibitors maintained similar soil NH4+ content, but at 30 days post-fertilization (DPF), the sorghum BNIs resulted in higher soil NO3− content than DMPP. Even so, these inhibitors managed to reduce 64% and 96%, respectively, of the NO3−-N/NH4+-N ratio compared to the control treatment. Similar to soil mineral N, there were no differences in leaf δ15N values between the two nitrification inhibitors, yet at 30 DPF, δ15N values from sorghum BNI were more positive than those of DMPP. N2O emissions from DMPP-treated soil were low throughout the experiment. Nevertheless, while sorghum BNIs also maintained low N2O emissions, they were associated with a substantial N2O emission peak at 3 DPF that lasted until 7 DPF. Conclusions: Our results indicate that while sorghum root exudates can reduce nitrification in field soil, even at the same efficiency as DMPP for a certain amount of time, they are not able to prevent the N pollution derived from N fertilization as DMPP does during the entire experiment. [ABSTRACT FROM AUTHOR]

To address problems of soil degradation, industrial farmers across the United States have converted to no‐till agriculture, which can mitigate the effects of soil erosion and reduce operating costs without necessarily compromising agricultural output. However, producers still debate the benefits of this practice. Through participant observation and semi‐structured interviews with 14 row‐crop farmers in central Indiana, this study examines farmer perceptions of no‐till as a soil conservation practice. Ethnographic findings reveal that adopters highlight no‐till's benefits for improving soil quality while also minimizing operating costs, including labor and fuel. However, both adopters and critics alike acknowledge trade‐offs; for example, no‐till disrupts entrenched management practices and norms—from the aesthetics of "clean" fields to the timing of spring planting. Furthermore, some non‐adopters argue that no‐till's heightened reliance on herbicide contradicts the broader goals of conservation. This study thus shows that while a compelling case can be made for no‐till as an environmental and economic "win‐win," this narrative also elides ongoing disagreements and trade‐offs linked to its adoption. No‐till's appeal for many producers is that it advances soil conservation without fundamentally challenging industrial farming's aspiration for ever‐increasing efficiency and profitability. [ABSTRACT FROM AUTHOR]

Community level physiological profiles (CLPPs) were used to characterize soils with two contrasting no‐till agricultural practices in terms of crop rotation, looking for differences in soil physiology according to management: 'good agricultural practices (GAP), based on crop rotation, and monocropping agriculture considered as poor agricultural practices (PAP); soils from nearby natural environments (NE) were used as reference. Soils from productive fields of the central Argentine Pampas were sampled in summer and winter. Treatments were replicated at four places along a 400‐km east–west transect, between longitudinal parallels 31° to 33°S. The CLPPs assay was based on either basal respiration or substrate‐induced respiration using different C sources, with or without additional nitrogen as a mineral amendment, to mimic fertilizer application effects. CLPPs allowed discrimination between soils with different agricultural practices, despite the differences in the texture and mineralogy of the soils at each replicate site. NE soils were significantly different to agriculture soils based on 70% of the estimated CLPPs parameters. The differences between GAP and PAP soils by CLPPs data were supported by 50% of the estimated parameters in winter and only by 12.5% of them in summer. The Euclidean distance between GAP and PAP increased 102% in winter compared with summer. Additional N to the incubation did not significantly modify the result. Coumaric and propionic acids appeared to be good substrates for discrimination between different agriculture practices by CLPPs. [ABSTRACT FROM AUTHOR]

The objective of this study was to elucidate the influence of long-term ecological farming on selected soil properties by comparing results obtained in the field with continuous conventional farming (CT) and those obtained in the field where the original CT was converted into ecological farming system with no-till practice (NT) twelve years earlier. Soil water retention curves were obtained for 100 cm3 undisturbed soil samples using a pressure plate apparatus. Hydraulic conductivity and the repellency index were assessed directly in the field using a mini disk infiltrometer. The examined soil properties showed that NT mostly had a positive influence on the soil quality. The soil water retention capacity represented by the saturated soil water content of 0.32 and 0.40 cm3 cm−3 and the reciprocal of the air-entry pressure head of 0.0227 and 0.0187 cm for CT and NT, respectively, was higher in the NT field than in the CT field. The soil physical quality, represented by the slope of the soil water retention curve at the inflection point of 0.033 (CT) and 0.047 (NT), was better under NT than CT. The hydraulic conductivity at the pressure head of –2 cm was higher in the NT field (0.97 cm hr.−1) than in the CT field (0.17 cm hr.−1). On the other hand, ecological farming increased water repellency (repellency index of 6.73 and 18.91 for CT and NT, respectively). [ABSTRACT FROM AUTHOR]

Of late, intensive farming for higher food production is often associated with many negative implications for soil systems, such as decline of soil organic matter (SOM), increase in risks of soil erosion by wind and/or water, decline in soil biological diversity, increase in degradation of soil physical quality, lower nutrient-use efficiency, high risks of groundwater pollution, falling water tables, increasing salinization and waterlogging, in-field burning of crop residues, pollution of air and emission of greenhouse gases (GHG), leading to global warming, and decline in factor productivity. These negative implications necessitate an objective review of strategies to develop sustainable management practices, which could not only sustain soil health and ensure food security, but also enhance carbon sequestration, decrease GHG emissions, and offer clean and better ecosystem services. Conservation agriculture (CA), that includes reduced or no-till practices along with crop residue retention and mixed crop rotations, offers multiple benefits. Adoption of a system-based CA conserves water, improves and creates more efficient use of natural resources through the integrated management of available soil nutrients, water, and biological resources, and enhances use efficiency of external inputs. Due to apparent benefits of CA, it is increasingly being adopted and now covers about 180 million hectares (Mha) worldwide. However, in South Asia its spread is low (<5 Mha), mostly concentrated in the Indo-Gangetic Plains (IGP). In this region, one of the serious issues is "residue burning" with severe environmental impacts. A huge amount of crop residue left over after the combine harvest of rice has forced farmers to practice widespread residue burning (∼140 M tonnes) to cope with excessive stubble and also for timely planting/sowing of succeeding crops. In rice-wheat cropping systems, which cover more than 10 Mha in the IGP, CA practices are relatively more accepted by farmers. In these systems, any delay in sowing leads to yield penalty of 1–1.5% per day after the optimum sowing date of wheat. The strong adoption of CA practices in IGP is mainly to overcome delayed sowing due to the field preparation and control of weeds, timely planting, and also escape from terminal heat during the grain-filling stage. Major challenges to CA adoption in South Asia are small land holdings (<1 ha), low technological reach to farmers, nonavailability of suitable farm implements for small farm holders, and the staunch conventional farming mind-set. South Asia region consists of many countries of diverse agro-ecologies with contrasting farming systems and management. This region, recently known for rapid economic growth and increasing population, necessitates higher food production and also hot-spots for adoption of CA technologies. Therefore, in this review critically explores the possibility, extent of area, prospects, challenges, and benefits of CA in South Asia. Conservation agriculture (CA), consisting of reduced or no-tillage and crop residue retention, is a self–sustainable system which offers an alternative to crop residue burning. The CA approach improves soil health by increasing soil organic carbon (SOC) and aggregation and also conserves soil, water and energy than conventional farming systems. South Asian countries are suitable for adoption of CA practices but the area under CA remains low (<5 Mha) as compared to the global area (180 Mha). Adoption of CA in South Asia has skewed distribution, mainly in Indo-Gangetic Plains (IGP) in India, Pakistan, Nepal and Bangladesh in South Asia. Development of herbicide-resistant weed species and weed shift by continuous application of herbicides are the major challenges in adoption of CA. The traditional-farming mind-set, socio-economic conditions, small farm-holdings, weed and residue management, and non-availability of suitable machinery are key constraints to the low adoption of CA practices in South Asia. [ABSTRACT FROM AUTHOR]

No-till practices play an important role in decreasing production costs, increasing soil organic matter content, improving soil structure and removing unwanted environmental impacts. However, due to a lack of access to proper machinery for direct seeding in unplowed lands, such practices have failed to produce successful results since they are incapable of providing sufficient contact between soil and seeds. Introducing a machine that can plant seeds and fertilizer at two different depths in hard (unplowed) soils covered with last season’s crop residues can be the first step towards pilot no-till initiatives. This step can finally lead to the promotion of this practice in the potential areas. In this study, different components of a disk furrow opener were optimally designed in Solid Works modelling software. ANSYS was used to analyze this furrow opener and its three main related components. Finally, the coulter’s stress was determined using the von Mises criterion. The result showed that the minimum coulter stress was 1985.5Pa throughout the plane and its maximum belonged to the holes inside the hub with 1.0819x107Pa. The safety factor of the initial coulter was 17.85, while that of the optimally designed coulter was 25.

Conservation agriculture (CA) is considered a sustainable practice with the potential to maintain or increase crop productivity and improve environmental quality and ecosystem services. It typically improves soil quality and water conservation; however, its effect on crop productivity is highly variable and dependent on local conditions/management. Crop residue retention plays a crucial role in CA and can help to improve overall soil health and ultimately crop productivity and sustainability. However, weed control, herbicide resistance, and weed shift under residue retained fields is a major challenge. Moreover, CA can increase water infiltration and reduce soil loss and runoff. This reduces the surface transport of nitrate and phosphorus from agricultural fields and the eutrophication of water bodies, although leaching of nitrate to groundwater can potentially increase. In addition, CA has been proposed as one of the components in climate-smart agriculture, owing to its reduced period to seed/plant next crop, reduced soil disturbance and low consumption of fossil fuels. Therefore, compared to the conventional intensive tillage, CA has a greater potential for soil C sequestration, favors higher soil biodiversity, lowers greenhouse gas emission, and can assist in mitigating climate change. However, not all experiments report a positive impact. The understanding and decoding the site-specific complexities of CA system is important and requires a multidisciplinary approach.

ABSTRACT: This study aimed to evaluate the effects of the quantity and soil position of Urochloa ruziziensis straw desiccated with glyphosate for different periods of time on ‘M-SOY 7908 RR’ soybean nodulation, growth and production characteristics. Three experiments were conducted under semi-controlled conditions. In the first, three quantities of U. ruziziensis straw (2.5, 5.0 and 10 ton ha-1) previously desiccated with glyphosate were incorporated into the soil (10 cm deep) or deposited on the soil surface, and in the second experiment, the treatments consisted of three U. ruziziensis desiccation periods, 0, 7 and 12 days before soybean sowing, and one treatment without U. ruziziensis. In the third treatment, desiccation was performed at 0, 5 and 10 days before soybean sowing, and the desiccated plant shoots were removed or left in place before soybean sowing. For each of the experiments, a completely randomized experimental design was adopted, and the masses of the shoot and root dry matter, the degree of nodulation and soybean production were evaluated. The deposition of U. ruziziensis straw on the soil surface promoted the nodulation and growth of ‘M-SOY 7908 RR’ soybean plant shoots, while its incorporation into the soil, even at 2.5 ton ha-1, caused deleterious effects. Desiccation of U. ruziziensis from 0 to 7 days before sowing was also detrimental to the nodulation and growth of M-SOY 7908 RR soybean, reducing its productivity.

ABSTRACT New strategies for sugarcane production have been very important since the incorporation of ethanol in the Brazilian energy mix in the early 1970s. Prior to planting sugarcane, the soil is prepared, and this process can affect root development and, consequently, sugarcane production. This study was conducted in an area of sugarcane crop renewal in the Cerrado biome (Brazilian tropical savanna), with the objective of identifying which tillage system generates the better root development and improved yield in sugarcane. The treatments were: 1) weed desiccation + moldboard plowing (0.4 m) + mild spike tooth harrowing (0.15 m); 2) subsoiler (0.3 m) + mild spike tooth harrowing (0.15 m); 3) weed desiccation + no-tillage (furrow opening and fertilizer); 4) weed desiccation + subsoiler (0.4 m); 5) ratoon destruction + subsoiler (0.4 m); 6) ratoon destruction + spike tooth harrowing (0.2 m) + moldboard plowing (0.4 m) + mild spike tooth harrowing (0.15 m). Characteristics of the sugarcane root system, such as the root length density, average distance between roots, and root soil exploration, after the first harvest (1.5 years) were studied. Root length density was greater for the treatments that included plowing (0.4 m) and harrowing (0.15 m) operations. The average distance between roots was low in the no-tillage system. The highest sugarcane yield in the plant crop was achieved by management practices with more extensive soil profile disturbances, like plowing followed by harrowing.

Reduced tillage and no-till farming technology is possible to employ only under particular soil conditions. The total land area of sites in Slovakia that are available for the application of reduced tillage is approximately 25.3% of agricultural land (20.4% very suitable and 4.9% less suitable), while 74.7% of soils are not suitable for this technological approach. Only 19.8% of soils (17.8% very suitable and 2.0% less suitable) are suitable for no-till farming technologies of soil preparation before sowing, while 80.2% of soils are not suitable for this method. The best conditions for these approaches are found in soil types such as Chernozems, Cutanic Luvisols, Mollic Luvisols, and Fluvisols, but also Albic Luvisols and Regosols located on plains, in lowland areas, and in lower altitude basins. In the higher altitude regions, we do not recommend employing these technologies. The identification of areas suitable for this method is possible using the information in the databases of the Soil Science and Conservation Research Institute in Bratislava, which have been managed in this study using a geographic information system. The input parameters were the altitude of a given locality, as well as the slope steepness, depth, stoniness, and texture of the soil. It turns out that GIS is also an appropriate means for identifying and categorizing landscapes and agricultural lands in order to implement differentiated (reduction) cultivation systems. [ABSTRACT FROM AUTHOR]

The objective of the research was to compare the energy cost and operating expenses of the main mechanized agricultural operations in soybean cropping, emphasizing the tillage / sowing operations and quantifying their possible savings using the conservation system, in relation to the conventional system in the plateau of Guanipa, state Anzoátegui, Venezuela, based on the hypothesis that it is possible in Los Riecitos, Municipality Freites, state Anzoátegui, to reduce in these works the energy cost in more than 10% in the exploitation of agricultural machinery. It was used in the experimental design an analysis of variance for the determination if there are or not significant differences between the population means of each variable and the treatments applied. For the determination of energy and exploitation costs was used the program "Energy and Exploitation Costs (CEE)". In each experimental unit were studied apparent density, humidity and soil resistance and also fuel consumption and energy cost. It is concluded that in the depths studied the physic-mechanical characteristics of the soils of the plots tested do not interfere in the application of the treatments. The system with the lowest energy cost, operating expenses and fuel consumption as a percentage was conservation (88.19% and 89.21% respectively). The technology used in the conservation system meant a saving of labor, by investing less time (4 h·ha-1) of use of the machinery. [ABSTRACT FROM AUTHOR]

Abstract: Conservation agriculture (CA) is widely promoted as a sustainable agricultural management strategy with the potential to alleviate some of the adverse effects of modern, industrial agriculture such as large‐scale soil erosion, nutrient leaching and overexploitation of water resources. Moreover, agricultural land managed under CA is proposed to contribute to climate change mitigation and adaptation through reduced emission of greenhouse gases, increased solar radiation reflection, and the sustainable use of soil and water resources. Due to the lack of official reporting schemes, the amount of agricultural land managed under CA systems is uncertain and spatially explicit information about the distribution of CA required for various modeling studies is missing. Here, we present an approach to downscale present‐day national‐level estimates of CA to a 5 arcminute regular grid, based on multicriteria analysis. We provide a best estimate of CA distribution and an uncertainty range in the form of a low and high estimate of CA distribution, reflecting the inconsistency in CA definitions. We also design two scenarios of the potential future development of CA combining present‐day data and an assessment of the potential for implementation using biophysical and socioeconomic factors. By our estimates, 122–215 Mha or 9%–15% of global arable land is currently managed under CA systems. The lower end of the range represents CA as an integrated system of permanent no‐tillage, crop residue management and crop rotations, while the high estimate includes a wider range of areas primarily devoted to temporary no‐tillage or reduced tillage operations. Our scenario analysis suggests a future potential of CA in the range of 533–1130 Mha (38%–81% of global arable land). Our estimates can be used in various ecosystem modeling applications and are expected to help identifying more realistic climate mitigation and adaptation potentials of agricultural practices. [ABSTRACT FROM AUTHOR]