Crop Rotation Systems Research Articles

Solving problems of optimizing crop rotation using genetic and ant algorithms

Issues of optimizing crop rotations are becoming key to increasing production efficiency and ensuring sustainable development of agriculture. Crop rotation is the systematic rotation of different crops in the fields over several years, which helps maintain soil fertility, reduce the risk of diseases and pests, and optimize the use of resources. The goal of the study is to develop effective strategies for managing crop rotations in order to optimize the use of resources and increase productivity. The paper presents strategies for managing a crop rotation system aimed at optimal distribution of areas for different crops, rational use of resources and emergency management. A genetic and ant algorithm is proposed for solving problems. The model is calibrated and validated using available data, followed by scenario analysis to evaluate different options.

CROP ROTATIONAL EFFECTS ON INFESTATION OF STEM BORERS IN RICE

The present study investigates the impact of crop rotation on the infestation of stem borers in rice crops. This research was carried out in the field at Shaheed Zulfiqar Ali Bhutto Agricultural College Dokri, Sindh, Pakistan. Several rotation practices were tested, including Rice fallow Rice, Rice-Wheat-Rice, Rice-Gram-Rice, Rice-Barseem-Rice, and Rice-Mustard-Rice. The results of the study revealed interesting findings. The lowest infestation rate, approximately 1.92% of rice stem borers, was observed in the Rice-Barseem-Rice rotation. This was followed by Rice-Mustard-Rice at 2.18%, Rice-Gram-Rice at 2.40% and Rice-Wheat-Rice at 3.21%. In contrast, the highest infestation rate, reaching 4.99%, was recorded in the Rice-fallow-Rice rotation system. These findings suggest that incorporating winter rotation crops such as Mustard, Barseem, and Gram into the cropping system can significantly reduce the population density of rice stem borers. On the contrary, mono-cropping, as exemplified by the Rice-fallow-Rice rotation, appears to favor stem borer infestations. In light of these results, it is recommended that further research and understanding be developed to implement cultural control methods and ensure ecological safety within winter crop rotation systems. This study underscores the importance of diversified crop rotation practices in mitigating the infestation of harmful pests like rice stem borers, contributing to sustainable agriculture and higher crop yields.

О ВЗАИМОЗАВИСИМОСТИ РАЗВИТИЯ ОРГАНИЧЕСКОГО СЕЛЬСКОГО ХОЗЯЙСТВА И ПРОМЫШЛЕННОГО ПРОИЗВОДСТВА ГУМИНОВЫХ УДОБРЕНИЙ

. In accordance with the Federal Law “On Organic Products and on Amendments to Certain Legislative Acts of the Russian Federation” No. 280-FZ dated August 3, 2018, Government Order No. 1788-r dated July 4, 2023 the Strategy for the Production of Organic Products until 2030 is approved. The Russian Ministry of Agriculture has been instructed to develop a road map for its implementation. The analysis of the main activities of the Strategy shows how the work of an agricultural producer should be structured in preparing the appropriate documentation for the organic products he produces. At the same time, in the Strategy there is not enough analysis and measures on the basis of which the material and technological base of agricultural organizations should be built. There is no definition of the concept of soil, soil fertility, to improve the crop rotation system based on the preservation of soil fertility with the use of long-acting organic fertilizers obtained from organic raw materials and the development of industrial capacities for its processing. The use of livestock and poultry waste for these purposes in accordance with the Federal Law of July 14, 2022 No. 248-FZ “On Livestock By-Products and on Amendments to Certain Legislative Acts of the Russian Federation”, which comes into force on March 1, 2023, allows for the creation of additional conditions for production of organic fertilizers. However, the projected volumes of demand for these fertilizers due to the sharp reduction in the cattle herd can be met by 35–40 %. A solution to this problem is possible by organizing the industrial production of organic fertilizers from peat and brown coal, the reserves of which in Russia are sufficient for these purposes

Potassium resources management systems in Chinese agriculture: Yield gaps and environmental costs

China is the world's largest consumer of chemical fertilizers, with a strong reliance on imports of mineral K fertilizer up to 50 %. Inexpensive and renewable straw-K recycling is crucial for enhancing soil K fertility and carbon (C) sequestration. Here, national management networks for inorganic- and straw-K were systematically integrated to identify yield gaps and C mitigation potential in Chinese typical crop rotation systems. National spatio-temporal changes in soil K fertility in the past 40 years were also mapped, indicating that about 52 % of national cereal arable cropland was still under low-K status in 2020. Compared with the inorganic K system (INK), grain yields of maize, wheat, and rice were respectively reduced by 9.4 %, 14.9 %, and 13.4 % under 0 K system, and increased by 5.2 %, 6.2 %, and 3.0 % under straw-based K recycling system (SBK system). Estimated net C emissions with the SBK system were 11.6 % (maize) and 47.4 % (wheat) lower than with the INK system, mainly due to the larger increase in soil C sequestration than in N2O production. Conversely, the SBK system increased net C emissions in rice by 57.6 % than the INK system due to larger increase in CH4 emissions. Scenario analyses showed that the annual C mitigation potential in the SBK system would approach 16.9 % (spring maize), 46.4 % (wheat-maize), 62.9 % (rice-wheat), and 22.4 % (rice-rice) by optimising the annual chemical fertilizer rate and seasonal straw distribution. Integrated inorganic- and straw-K management could also be extended to other K-limited developing and less-developed regions to enhance global food security and agricultural green development.

Yield of spring durum wheat against the background of cellulolytic activity of the soil

Long-term studies were carried out in the field at the station on crop rotations and monocultures of the department of agriculture and resource-saving technologies of the Federal State Budgetary Scientific Institution "FNTs BST RAS", located in the Orenburg region (51.775125° N and 55.306547° E.). The purpose of the study was to establish the influence of the cellulolytic activity of the soil and the quantitative content of nitrate nitrogen in the soil in combination with meteorological factors on the yield of wheat grown for many years (21 years) in crop rotations and monoculture in the Southern Urals. The object of the study is spring durum wheat cultivated in crop rotations of various rotations, a set of crops and monoculture, as well as soil samples according to the experimental options. When determining the cellulolytic activity of the soil, the method of decomposition of linen fabric under the influence of microorganisms was used. The yield of durum wheat is influenced by such factors as predecessors, including their aftereffect in the crop rotation system, as well as the prolonged effect of mineral fertilizers. The average yield of durum wheat (for 21 years of research) in six-field crop rotations is 0.71 t/ha, with fertilizer 0.76 t/ha. Cultivation of durum wheat in two field crop rotation increases its yield by 0.07 t, in six fields 0.23 t/ha relative to monocultivation of the crop according to two backgrounds of soil nutrition. Cultivation of durum wheat in a six-field crop rotation on green manure fallow is accompanied by increased cellulolytic activity (12.0%). In the monoculture of durum wheat, the consumption of N-NO3 during the growing season increases to 20 mg with fertilizer up to 16 mg per kg of soil on an unfertilized background, which is associated with an increase in weediness and consumption of the macronutrient by the weed component. The share of output of grain units of durum wheat in six-field crop rotations is up to 16.3%, in two-field crop rotations up to 47.9%, with mono-cultivation of crops 100%.

Effect of Common Vetch (Vicia sativa L.) Green Manure on the Yield of Corn in Crop Rotation System

Regenerative farming systems are gaining increasing attention in crop production worldwide. The challenge of the future is to find and apply farming methods that not only reduce the carbon footprint of cultivation, but also produce sustainably through an optimal choice of inputs. We set up our crop rotation experiment in 2019 in order to evaluate the role of common vetch (Vicia sativa L.) as a green manure crop in a crop rotation system. The results were compared with nitrogen fertilizer (80 kg ha−1 N) and control (no green manure and no fertilizer) treatments. Based on the three years of results, it can be concluded that the biomass production capacity of common vetch sown in August is determined by the amount of precipitation in October under continental climatic conditions. In an optimum year for corn, common vetch as a forecrop was found to be equivalent to the effect of fertilizer application at all three applied seed rates, but under stress conditions in a drought year, significantly higher corn yields were obtained when common vetch green manure was applied. Our results suggest a justified role for the use of common vetch green manure in crop rotation systems.

Nitrogen fixation of lablab and finger millet in South‐India

AbstractBackgroundIn a long‐term rotation experiment (2016–2022) with different nitrogen (N) fertilizer levels in subtropical South‐India, crop yields of low N plots were unexpectedly high. We therefore hypothesized that in the absence of mineral N application, these yields are largely due to N inputs by N2 fixation in the component crops. To assess the diazotrophic N2‐fixation of lablab (Lablab purpureus L. Sweet) and possible associative N2‐fixation of finger millet (Eleusine coracana L. Gaertn), a controlled experiment was conducted during the 2021 monsoon season within the above‐mentioned long‐term field study. Two approaches were used to estimate the quantity of N derived from the atmosphere (Ndfa): the dilution method using a 15N‐labeled fertilizer and the natural abundance method.MethodFor the 15N dilution method irrigated maize (Zea maize L.), finger millet and lablab were labeled with two split applications of 10% 15N fertilizer (50:50 15N‐urea and 15N‐ammonium sulfate) amounting to a total of 15 kg N ha−1. Maize was selected as the non‐fixing reference plant to estimate diazotrophic N2‐fixation. The entire aboveground biomass of the labeled plants was harvested at maturity and analyzed for total DM, N concentration, and the 15N isotope ratio.ResultsN2 fixation efficiency for lablab was 52%–69% depending on the calculation method, corresponding to 40–53 kg N ha−1. For finger millet, the natural abundance method resulted in an estimated N2‐fixation of 5 kg N ha−1, which was suggested by the results of the dilution method whereby the reference plant maize was only poorly labeled.ConclusionLabeling of maize might have been diluted due to unexpected associative N2‐fixation or N‐uptake from unlabeled deep soil N pools. The data underline the importance of symbiotic N2‐fixation in crop rotation systems of South‐India.

Inhibition mechanism of atrazine on soybean growth insight from the plant nitrogen fixation and rhizobia diversity inhabiting in nodules and rhizosphere soil

Atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] is a herbicide widely used in corn production. However, when used under corn-soybean rotation system, it decreases soybean yield. The toxicology mechanisms of atrazine on soybean are rarely studied from the perspective of rhizobia-soybean symbiont formation and nitrogen fixation. In this study, under atrazine stress, high-throughput sequencing of rpoB was performed to evaluate rhizobial diversity in the nodules and soybean rhizosphere, and the correlation between physiological indicators of plant growth and rhizobial diversity was explored. The results revealed that atrazine inhibited soybean growth by disrupting glutamate synthetase activity to reduce total nitrogen (TN) content in the plant. Atrazine altered the nodule structure and reduced leghemoglobin content. High-throughput sequencing of rpoB revealed that the inhibition rate of Afipia genosp. 3 in the nodules under atrazine stress (20 mg·kg−1) was >80 % higher than that in the control (no atrazine). The abundance of Rhizobium leguminosarum and Rhizobium sp. CF142 decreased in the nodules but increased in rhizosphere soil. The abundance of Afipia genosp. 3 and Bradyrhizobium sp. AD1_1_nodule in rhizosphere soil was negatively correlated with TN content and glutamate synthetase activity in soybean. Moreover, soil nitrate nitrogen (NO3−-N) content was the essential factor influencing the rhizobial community diversity under atrazine stress. This study contributed to clarifying the molecular biological mechanism of the effect of atrazine on rhizobia-soybean symbiont formation and nitrogen fixation. Moreover, this study provided new directions and ideas for the subsequent development and application of related prevention and control measures, which can contribute to the more comprehensive development of corn-soybean crop rotation system and ensure the sustainable use of black soil.

Life cycle assessment of four different precision agriculture technologies and comparison with a conventional scheme

Precision farming technologies have the potential to enhance agricultural sustainability, but their exact environmental impact remains uncertain. This study aimed to (1) compare the life cycle assessment (LCA) of a conventional five-year crop rotation system with and without precision agriculture technologies (PATs) in Lower Austria; (2) to assess the emission hotspots and (3) to perform a sensitivity analysis on fertilization using the DeNitrification-DeComposition (DNDC) soil model to quantifying soil emission. Evaluated PATs included automatic steering systems, automatic section control (ASC), proximal sensors, and prescription maps from remote sensors. The crop rotation system included spring barley, soy, winter wheat, rapeseed, and winter barley. Assessed agricultural processes encompassed tillage, seeding, plant protection, fertilization, and harvesting. The impacts evaluated were climate change, fine particulate matter formation, freshwater eutrophication, freshwater ecotoxicity, terrestrial acidification, terrestrial ecotoxicity, and human carcinogenic toxicity. The sensor scheme scenario showed the highest reductions in climate change, followed by the prescription map, ASC, and autosteer scheme with reductions of −17.0, −8.9, −6.4, and −2.4%, respectively. This study emphasizes the potential of PATs to minimize environmental impacts in crop production while recognizing the influence of site and technology-specific factors. Future research should consider local variables for a comprehensive environmental assessment.

Boll distribution in the cotton canopy is affected by nitrogen management and cover crops in a sandy soil under water scarcity

Context or problemA favorable cotton boll distribution within the plant canopy can promote early fruit retention and increase crop yield and fiber quality, particularly in rainfed crops in sandy soils that are subject to periodic water deficits. However, the effects of different cover crop rotation systems combined with different nitrogen (N) rates and sources on boll distribution and cotton earliness are unknown. Objective or research questionThe objective of this study was to evaluate the boll distribution and earliness of cotton as a function of the cover crop rotation system and N sources and rates, in a sandy soil of a tropical region of Brazil prone to drought. MethodsA field study was carried out for two growing seasons (2018–2020) in southeastern Brazil in an area with sandy soil. The treatments consisted of the following crop rotation systems, which were implemented in 2016: Fallow; single grass; grass + grass; grass + legume; and MIX (grass+legume+grass). In addition, N rates of 70, 100, and 130 kg ha−1 (applied as topdressing) and two N sources (urea; and controlled-release urea, CRU) were evaluated. ResultsLow water availability in the 2018/2019 crop season resulted in early plants that reached 95% boll yield below fruiting node 12 when 70 kg ha−1 N (urea) was applied. Satisfactory rainfall in the 2019/2020 crop season resulted in 95% boll yield below fruiting node 14 when 130 kg ha−1 N was applied for all N sources and rotation systems. Applying CRU increased the boll distribution in the top third of the plant. Applying 130 kg ha−1 N increased the boll distribution in the middle and top thirds of the plant, particularly in the treatments with legume cover crops and CRU. In the crop season with higher rainfall and yield potential, the rotation systems without legumes that received 70 kg ha−1 N (urea) had a lower boll distribution in the top third of the plant. ConclusionsCotton boll distribution is affected by cover crop rotation systems, N rates and sources and water availabity throughout the season. The best strategy for improving early boll setting is to apply lower rates of N as CRU in a rotation system with a mixture of grasses and legumes as cover crops. Additionally, there is still a challenge to increase the cotton earliness in years with high water availability. Implications or significanceCover crops and increased efficiency fertilizers are important to improve boll setting throughout the entire cotton canopy. Because these technologies improve the availability of nitrogen and water in the soil, especially in dry years. Improving cotton earliness is still a challenge in low-altitude regions, since plant cycle is naturally short in these environments, due to the greater accumulation of degrees days. Even so, the use of lower N rates associated with cover crops and controlled-release urea may have a small increase in cotton earliness, but mainly help in early fruit retention.

Insecticide contamination in organic agriculture: Evidence from a long-term farming systems comparisons trial

Synthetic pesticides applied in conventional agriculture to control pests tend to compromise ecosystem services, and their residues may contaminate organic agriculture. To understand the significance of this contamination, also in small-scale farming systems in sub-Saharan Africa, quantitative data is required. Therefore, we compared synthetic insecticide and botanical/biopesticide residues in conventional and organic agricultural production systems after nine years of continuous cultivation of a maize-based crop rotation system at two sites in Kenya. Our results show high detectable concentrations of synthetic insecticide residues (imidacloprid, acetamiprid, chlorpyrifos, and chlorantraniliprole) in conventional plant produce and soil. Furthermore, the organophosphate chlorpyrifos was detected at concentrations above European Union Maximum Residue Limits (MRL) for plant produce, indicating potential risks for human health. Additionally, we detected imidacloprid, acetamiprid, chlorpyrifos, and chlorantraniliprole concentrations in the soil, indicating potential environmental harm. No residues of biopesticide/botanicals were detected in any of the production systems. However, we detected imidacloprid and chlorantraniliprole in organic plots. The findings indicate that the MRLs can be crossed even if synthetic insecticides are applied according to or below the recommended rates on the conventional plots. Thus, synthetic insecticides potentially risk human health and the environment, while botanicals and bio-pesticides represent a safe alternative.

Shaping the succession patterns of different soil nutrients, enzyme stoichiometry, and microbial communities through rotation systems

The ecological environment and function of farmland soil are strongly affected by crops. However, there is still a lack of understanding of how the soil microbial environment responds to crop changes in rotation systems. Therefore, we studied wheat–maize (W–M) and garlic–maize (G–M) crop rotation systems to explore the responses in terms of soil nutrients and the microbial community to different tillage systems. The results showed that the W–M cropping system was continuously limited by phosphorus nutrition, and the G–M cropping system was alternately affected by nitrogen and phosphorus nutrition due to the different nutrient requirements of crops. The bacterial communities were significantly affected by the cropping systems and crop types, whereas the fungal communities were only affected by the crop types. Compared with W–M, G–M increased the abundances of Nitrospirae, Bacteroidetes, and Rokubacteria in the bacterial community, and decreased the abundance of Basidiomycota in the fungal community, as well as increasing the nodes and links between bacterial communities but weakening the links between fungal communities. Compared with W-M, G-M decreases the contents of soil organic carbon and total nitrogen, increases the diversity and abundance of bacteria, and decreases the diversity of fungi, thereby reducing extracellular enzyme C/N and N/P, and increasing the activity ratio of C/P, ultimately reduces C and P limitations and increases N limitations. Differences in crop types result in greater changes in soil bacteria than fungi in crop rotation systems. Our study provides more insights into the relationship between soil nutrient limitation and microenvironment in rotation systems.

Nitrogen rhizodeposition from corn and soybean, and its contribution to the subsequent wheat crops

Nitrogen (N) is a key factor in the positive response of cereal crops that follow leguminous crops when compared to gramineous crops in rotations, with the nonrecyclable rhizosphere-derived N playing an important role. However, quantitative assessments of differences in the N derived from rhizodeposition (NdfR) between legumes and gramineous crops are lacking, and comparative studies on their contributions to the subsequent cereals are scarce. In this study, we conducted a meta-analysis of NdfR from leguminous and gramineous crops based on 34 observations published worldwide. In addition, pot experiments were conducted to study the differences in the NdfR amounts, distributions and subsequent effects of two major wheat (Triticum aestivum L.)-preceding crops, corn (Zea mays L.) and soybean (Glycine max L.), by the cotton wick-labelling method in the main wheat-producing areas of China. The meta-analysis results showed that the NdfR of legumes was significantly greater by 138.93% compared to gramineous crops. In our pot experiment, the NdfR values from corn and soybean were 502.32 and 944.12 mg/pot, respectively, and soybean was also significantly higher than corn, accounting for 76.91 and 84.15% of the total belowground nitrogen of the plants, respectively. Moreover, in different soil particle sizes, NdfR was mainly enriched in the large macro-aggregates (>2 mm), followed by the small macro-aggregates (2–0.25 mm). The amount and proportion of NdfR in the macro-aggregates (>0.25 mm) of soybean were 3.48 and 1.66 times higher than those of corn, respectively, indicating the high utilization potential of soybean NdfR. Regarding the N accumulation of subsequent wheat, the contribution of soybean NdfR to wheat was approximately 3 times that of corn, accounting for 8.37 and 4.04% of the total N uptake of wheat, respectively. In conclusion, soybean NdfR is superior to corn in terms of the quantity and distribution ratio of soil macro-aggregates. In future field production, legume NdfR should be included in the nitrogen pool that can be absorbed and utilized by subsequent crops, and the role and potential of leguminous plants as nitrogen source providers in crop rotation systems should be fully utilized.

Crop yield increments will enhance soil carbon sequestration in coastal arable lands by 2100

Coastal lands are crucial arable land reserves that play a vital role in ensuring future global food security. In arable coastal lands, low soil quality often results in limited crop yield and soil organic carbon (SOC), making them promising sites for enhancing both soil carbon sequestration and agricultural production. However, a scarcity of long-term site experiments has led to a research gap regarding SOC sequestration in coastal arable lands, leaving potential uncertainties due to variations in planting systems, crop yields, and the influence of climate change. In this study, we focused on the Yellow River Delta (YRD) in China, which is a typical coastal agricultural area. We verified the adaptability of the Denitrifcation-Decomposition (DNDC) model in coastal farmlands based on an 11-year long-term observation experiment and continuous sampling survey data. We further explored the spatiotemporal changes of regional SOC stocks under two Shared Socio-Economic Pathways (SSPs) scenarios based on five Global Climate Models (GCMs) derived from the Coupled Model Intercomparison Project Phase 6 (CMIP6), along with three yield increase scenarios from 2020 to 2100. The results indicated that promoting single-cotton cultivation in coastal saline–alkali lands would result in at least 88.2% of farmland being converted into carbon sinks. In contrast, promoting the cultivation of a wheat–maize rotation system can promote regional SOC sequestration as a whole, with a maximum increase of 31.90 Mg C ha−1. By 2100, the SOC stocks decreased in cotton and wheat–maize rotation farmland by 3.9% and 11.6%, respectively, in the SSP585 scenario compared with that in the SSP126 scenario. Except for farmlands with wheat-maize rotation cropping system under the SSP126 scenario, the SOC stocks in all other scenarios are projected to reach their theoretical maximum values before 2050. Additionally, when reaching the North China Plain (S1) and national (S2) high-yield levels of farmland, the SOC stocks in cotton farmland by 2100 increased by 16.7% and 21.6%, respectively, whereas the SOC stocks in wheat-maize farmland increased by 1.8% and 4.8%, respectively. Our study revealed the mutually beneficial relationship between yield increment and SOC sequestration in coastal farmlands under climate change, as well as the potential for future SOC sequestration. We provided scientific support for land management and climate change mitigation strategic decision-making in coastal saline–alkali farmlands.

Soil Tillage and Cropping System Effects on the Physical-Hydric Properties of a Soil under No-Tillage

A no-tillage system (NT) is an alternative to replace soil management with intense soil tillage and degradation. Our objective was to evaluate the physical–hydric properties of soil under NT for four years after undergoing 13 years of minimum (4NTM) and conventional tillage (4NTC) with reference to continuous NT for 17 years (17NT). The soil bulk density, porosity, storage capacities of water and air, visual evaluation of soil structure (VESS), and saturated hydraulic conductivity were determined. The root dry biomass of soybean, maize, and palisade grass was also measured. NT during four years established after receiving 13 years of tillage did not significantly affect soil properties compared to 17NT, which means that four years of NT reached structural stability similar to continuous 17NT. The VESS scores were less sensitive to identifying soil compaction. Crops have no significative influence on soil properties, but the roots of maize seem to be less sensitive to soil compaction, which is important considering it is in a crop rotation system. The treatments (soil tillage and crop rotation) presented soil compaction below a 10 cm depth, and to our loamy textural class soil, a Bd > 1.60 Mg m−3 restricted soil aeration due to macroporosity < 0.10 m3 m−3.

Assessing soil structural quality as an indicator of productivity under semi-arid climate

A near real-time evaluation of the management system's impact on soil conditions requires a quick and straightforward framework to help farmers with a reliable on-farm assessment. The visual soil evaluation methods can potentially be used as a reliable on-farm approach for assessing soil physical quality. This research aims to better understand the importance of visual soil evaluation for productivity in semi-arid climates. The objectives were to evaluate the ability of Visual Evaluation of Soil Structure (VESS) and Double Spade (DS) under agricultural systems in a semi-arid region and to assess the relationship between soil structural quality and crop yield. Forty arable sites under rain-fed and irrigated farming with crop rotation and mono-cropping systems were studied, and twenty-one physical and bio-chemical soil properties were determined at two depths (0–20 cm and 20–40 cm). VESS and DS were conducted at each farm. The reliability of visual approaches was evaluated using measured soil properties and their capability to detect the impact of management systems. Soil quantitative measurements and crop yield information were deployed to assess soil productivity and its relationship with soil physical quality. The overall assessment of soil properties indicated a better soil condition for irrigated farming with crop rotation. The visual scores were in a range of 1.5–3.4 for VESS and a range of 1.9–3.5 for DS. The mean scores of VESS and DS were different between rain-fed and irrigated farms (P < 0.05), and visual methods were able to differentiate between mono-cropping and crop rotation (P < 0.05). The best soil structural quality was associated with the highest level of crop yield, and visual approaches were able to detect the differences in wheat yield levels (P < 0.05). The scores of VESS and DS were significantly correlated with soil properties (r > 0.6). Both VESS and DS indicated good efficiency for a practical on-farm assessment of soil conditions under agricultural management in northwest Iran and similar ecosystems. A close relationship between crop yield and soil structural quality was obtained, which indicated that the optimum soil structural condition plays an important role in the sustainability of crop production in semi-arid cultivation.

Crop rotation and inoculation increase soil bradyrhizobia population, soybean grain yields, and profitability.

Crop rotation and rhizobial inoculation are strategies to increase yield by means of organic matter addition and modulation of microbial diversity. However, the extent to which these agricultural practices change soil Bradyrhizobium populations, soybean grain yield, and economic benefits to farmers is unclear. Thus, this study aimed to evaluate the interaction between crop rotation and inoculation of soybean (Glycine max) cultivated in two contrasting soils (clayey and sandy soil) on biological nitrogen fixation components, grain yields, and profits. Field experiments with a three-year crop rotation system were carried out to compare effects of inoculation and crop rotations on soil chemical attributes, bradyrhizobia most probable number (MPN) and diversity, soybean nodulation, grain yield, and economic indicators of inoculation in different crop rotations. The crop rotation did not affect the soil MPN cells of bradyrhizobia, but the inoculation and the soil sampling time did, ranging from 3.61-4.42 to 4.40-4.82 in the sandy soil, while in the clayey soil they were from 5.19-6.34 to 6.61-7.14 in Log10 per g of soil with higher population after harvest of summer crops. In the clayey soil, crop rotation influenced soybean nodulation. The grain yield of inoculated soybean in the clayey soil was higher than that in the sandy soil. Soybean inoculation with Bradyrhizobium spp. increased the profitability of agricultural production systems by up to 45% in clayey soil and up to 7% in sandy soil.

Cropping rotation improved the bacterial diversity and N-cycling genes in tobacco fields through a 19-year long-term experiment

Soil microorganisms play crucial roles in various processes within the soil ecosystem, such as nutrient cycling, organic matter decomposition, and maintenance of soil structure. However, their responses to fertilization and different cropping systems in tobacco soils remain poorly understood. In this study, we conducted a 19-year-long field experiment on rice-tobacco rotation cropping (R) and continuous tobacco cropping (C), with three fertilization treatments: no fertilizer (NF), chemical NPK fertilizer (NPK), and composted pig manure (OM). The composition, co-occurrence patterns, N-cycling genes (nifH, AOA-amoA, AOB-amoA, nirS, nirK, and nosZ) of the bacterial communities as well as the soil properties were analyzed in the soils after tobacco was harvested. The pH and available potassium (AK) in the rotation cropping soil were significantly lower than those in continuous cropping soil, while the α-diversity index, and the abundance of nifH, nirS, nirK, and nosZ genes were opposite. The phyla Chloroflexi, Desulfobacterota, MBNT15, and Nitrospinota, as well as number of low-abundance genera, were significantly enriched in rice-tobacco rotation cropping. Partial least squares path model (PLSPM) indicated that cropping systems had a greater influence on the variations in bacterial communities compared to fertilization practices. These findings enhance our understanding of the significance of land management and fertilization in shaping the soil bacteria of tobacco. The rice-tobacco rotation cropping system demonstrated greater benefits to soil microorganisms and N-cycling genes compared to continuous cropping system.

The influence of organo-mineral fertilizers on the yield and quality of oilseed flax in northern Kazakhstan

The article shows that in the agro-industrial complex of Northern Kazakhstan, much attention is paid to the issues of progressive improvement of soil fertility, crop yields, increasing the production of grain, feed and other crops based on a scientifically based farming system. Currently, the acreage should be carried out in the crop rotation system and a special place is occupied by the problem of providing the population with high-protein and balanced fatty foods. The introduction of oilseed flax into diversified types of field crop rotations contributes not only to providing the national economy with oilseed products, but also to improving the agrophysical, biological and agrochemical properties of ordinary chernozems. In addition, flaxseed contains a large amount of balanced and easily digestible protein, vegetable oil, various sugars and carbon waters, as well as essential vitamins and trace elements needed in the diet. Field experimental studies were conducted to identify the effect of the effectiveness of mineral and organic fertilizers on improving soil fertility, the formation of the size and quality of flax crops, and to determine the most effective option in the northern region of Kazakhstan. The optimal use of mineral and organic fertilizers caused a positive effect of flax plant cenosis on the density, in particular, on the field germination of plants, plant growth dynamics, accumulation of raw and dry mass of flax plants. The optimal use of mineral and organic fertilizers contributed in addition to increasing soil fertility on plant yields and profitability of growing oilseed flax.

Management practices regulate the response of canopy and ecosystem water use efficiency in cropland ecosystems

ContextWith rising global temperature and frequent drought events, water resource supply is facing to great challenge. Understanding the effects of different management practices on cropland water use efficiency (WUE) is crucial to promote effective allocation of water resources and food security. ObjectiveThe objective of this study was to reveal the contrasting effects of different farm management practices including continuous and rotational, tillage and no-till, irrigated and rainfed on cropland water use efficiency from canopy (WUET) to ecosystem (WUEET) scales, respectively. MethodsOn the basis of 26 site-years eddy covariance-based carbon and water flux observations, this study used the underlying WUE (uWUE) model to partition evapotranspiration (ET) across maize and soybean ecosystems. Three control groups were used to compare the effects of different management practices on the coupling relationships between terrestrial carbon and water cycles, respectively. ResultsCompared with the rotational maize-soybean site, both WUET and WUEET at the continuous maize site were larger, which was mainly ascribed to stronger gross primary productivity (GPP) for the C4 crop. But over the maize-planting years, both WUET and WUEET at the rotational site were higher than the continuous site owing to the nitrogen fixation by rhizobia for preceding year, especially for WUET. Under conventional tillage and no-till management, multi-year mean WUEET and WUET were contrasting. WUEET under no-till was apparently larger than WUEET under till, because of similar GPP but relatively lower ET. Meanwhile, more water was consumed by crop transpiration (T) under no-till, which led to lower WUET in comparison with WUET under till. In comparison with the rainfed farming, GPP, ET and T all increased apparently after irrigation. However, both WUET and WUEET at the irrigated site were not improved owing to more water lost with relatively fewer GPP increase. ConclusionsThe study suggested that the crop rotation system can improve both WUEET and WUET apparently. Meanwhile, fewer water resource was consumed by cropland under no-till management. Finally, irrigation farming improved the cropland GPP but reduced WUEET and WUET. ImplicationsOur results provide valuable management implications for understanding the mechanisms that can enhance water use efficiency and result in significant water savings and high yield.