Differences In Crop Yield Research Articles

Phosphorus fertiliser application and the subsequent cadmium input in three provinces along Yangtze River region of China

ABSTRACT This study has undertaken an analysis of phosphorus fertiliser use in three provinces from 2010 to 2020: Sichuan, Hubei and Jiangsu along the Yangtze River basin. It was revealed that phosphorus fertiliser application rate of Hubei experienced the most significant reduction, and the application rate of Sichuan was the lowest, but its yield of different crops hardly decreased. The yield for all food crops by Jiangsu was highest, indicating the importance of strong economic development on sustainable agriculture practice. Cd input for Hubei was highest. In Jiangsu, Xuzhou, Lianyungang, and Suqian are the three cities applying the most phosphorus fertiliser, which also happen to be the cities with lowest GDP. The findings of this research could provide useful insights into the current practice of phosphorus fertiliser application in the main rice planting regions of China and facilitate the optimal use of global sustainable intensification of agricultural systems.

Impact of mulching and nutrient management under pulses based cropping systems on vertisols of southern transitional zone of Karnataka

A field experiment was conducted to study the effect of mulching and nutrient management under different pulse based cropping system during 2018-19 at Indian Institute Pulses Research, Regional Research Station, Dharwad, Karnataka, India. The field experiment was conducted in deep black soil using split-split plot design with three replications. The treatments comprised of four cropping systems i.e., maize-chickpea, soybean-chickpea, groundnut-chickpea and mungbean-sorghum and two levels of fertilisation (farmers practise and recommended rate of fertilisers) with mulching and without mulching. The pooled yield of different crops under cropping system was significantly higher with mulching and recommended rate of fertilizer application. Among the different cropping systems, maize-chickpea was recorded significantly higher chickpea equivalent yield (3867 kg/ha) compared to other cropping system. Application of recommended rate of fertilizers resulted in higher chickpea equivalent yield of 2794 kg/ha over farmers’ practice. Among the mulching practices, mulching with crop residues recorded significantly higher chickpea equivalent yield of 4257 kg/ha over no mulching (3754 kg/ha). Higher yields of component crops are reported in recommended rate of fertilisers with mulching. Hence, for realising higher system productivity and net returns, it is better to grow maize during kharif season followed by chickpea in rabi season with recommended rate of fertilisers and crop residue mulching for in-situ moisture conservation.

Vermicompost Leachate-Based Biostimulant and its Effects on Physiological Variables and Yield of Different Crops in Manabí, Ecuador

Using large volumes of synthetic chemical fertilizers is a general practice in modern agriculture at a high economic and environmental cost. Biostimulants have become an alternative to this routine due to their ability to stimulate plant physiological processes without polluting soil and water. In Ecuador, however, little research has been carried out on the effect of biostimulants on the yield of crops of agricultural interest. The objective of this research was to determine the effect of foliar application of a biostimulant based on bovine manure vermicompost (VCLB) leachates on physiological variables and the yield of corn, cotton, and peanuts under field conditions and chard and five pepper hybrids in semi-protected cultivation under the agro-climatic conditions of the province of Manabí, Ecuador. The nine experiments carried out with the species and hybrids included various dilutions of VCLB and controls consisting of fertilization with nitrogen, phosphorus, and potassium, depending on the species, and soil without fertilizer. In all species, VCLB-induced plant length, chlorophyll content, and crop yield exhibit equal or higher statistical differences than those achieved under chemical fertilization (NPK). These results demonstrate the potential of this biostimulant as a sustainable alternative to produce these crops, reducing potentially the adverse effects of production on the environment under the tropical conditions of Manabí, Ecuador. We recommend corroborating these results with production-scale research.

Trichoderma cf. asperellum and plant-based titanium dioxide nanoparticles initiate morphological and biochemical modifications in Hordeum vulgare L. against Bipolaris sorokiniana

BackgroundSpot blotch is a serious foliar disease of barley (Hordeum vulgare L.) plants caused by Bipolaris sorokiniana, which is a hemibiotrophic ascomycete that has a global impact on productivity. Some Trichoderma spp. is a promising candidate as a biocontrol agent as well as a plant growth stimulant. Also, the application of nanomaterials in agriculture limits the use of harmful agrochemicals and helps improve the yield of different crops. The current study was carried out to evaluate the effectiveness of Trichoderma. cf. asperellum and the biosynthesized titanium dioxide nanoparticles (TiO2 NPs) to manage the spot blotch disease of barley caused by B. sorokiniana and to assess the plant’s innate defense response.ResultsAloe vera L. aqueous leaf extract was used to biosynthesize TiO2 NPs by reducing TiCl4 salt into TiO2 NPs and the biosynthesized NPs were detected using SEM and TEM. It was confirmed that the NPs are anatase-crystalline phases and exist in sizes ranging from 10 to 25 nm. The T. cf. asperellum fungus was detected using morphological traits and rDNA ITS analysis. This fungus showed strong antagonistic activity against B. sorokiniana (57.07%). Additionally, T. cf. asperellum cultures that were 5 days old demonstrated the best antagonistic activity against the pathogen in cell-free culture filtrate. Also, B. sorokiniana was unable to grow on PDA supplemented with 25 and 50 mg/L of TiO2 NPs, and the diameter of the inhibitory zone increased with increasing TiO2 NPs concentration. In an in vivo assay, barley plants treated with T. cf. asperellum or TiO2 NPs were used to evaluate their biocontrol efficiency against B. sorokiniana, in which T. cf. asperellum and TiO2 NPs enhanced the growth of the plant without displaying disease symptoms. Furthermore, the physiological and biochemical parameters of barley plants treated with T. cf. asperellum or TiO2 NPs in response to B. sorokiniana treatment were quantitively estimated. Hence, T. cf. asperellum and TiO2 NPs improve the plant’s tolerance and reduce the growth inhibitory effect of B. sorokiniana.ConclusionSubsequently, T. cf. asperellum and TiO2 NPs were able to protect barley plants against B. sorokiniana via enhancement of chlorophyll content, improvement of plant health, and induction of the barley innate defense system. The present work emphasizes the major contribution of T. cf. asperellum and the biosynthesized TiO2 NPs to the management of spot blotch disease in barley plants, and ultimately to the enhancement of barley plant quality and productivity.

Physiological evaluation of Sonchus oleraceus L. seeds with different pre-germinative treatments under high tropical latitudinal conditions

Sonchus oleraceus L. is an invasive species that negatively affects the quality and yield of different crops. This research aimed to evaluate the physiological behavior of seeds from the weed S. oleraceus L., which were subjected to different treatments in three experiments. In experiment 1, different gibberellic acid (GA) concentrations were applied (0, 200, 400, and 600 mg L-1). In the second experiment, apical, basal, and apical-basal cut treatments were carried out on the seeds. In a third experiment, seeds were placed at different sowing depths (0.5, 1, 2, 5, and 10 cm) in peat as the substrate. The results indicated that GA at concentrations higher than 200 mg L-1 inhibited seed germination and, consequently, seedling growth. Germination was similar between the 200 mg L-1 GA treatment and the control, but germination occurred faster in the control. The apical-basal cut in the seeds generated the highest percentage of germination, the highest average speed of germination, and a significantly lower time of germination than the control; however, the longest shoot was observed in the seeds without a cut, and the longest root was detected in the seeds with the basal cut. Seedling emergence was affected by sowing depth, where it was significantly greater at 0.5, lesser at 2 cm, and, at greater depths, seedlings did not emerge.

Unraveling the devastating impact of Tomato Leaf Curl New Delhi Virus (ToLCNDV): understanding its characteristics, host range, and management strategies

Due to their stagnation, plants are frequently exposed to a variety of stresses, including both abiotic and biotic factors. Biotic stress in plants is due to many microbes that include viruses, fungi, bacteria, and parasitic organisms as plant pathogens. Plant viruses are one of those pathogens that frequently evolve and lower global agricultural productivity. Geminiviruses are the most damaging type of plant viruses. Tomato Leaf Curl New Delhi Virus (ToLCNDV) is a begomovirus belonging to the family Geminiviridae. This is a ssDNA virus having a bipartite genome with genomic length ranging between 2.6-2.7 kb. This virus was originally discovered in India in 1995 from tomato (Lycopersicon esculentum). It mostly infects solanaceous and cucurbitaceous crops and is a whitefly-transmitted, circulative and persistent virus. Its prominent symptoms are severe upward leaf curling, enations, stunting, puckering, yellow spots and yellow mosaic. This virus has devastating effects on the yield of different crops with yield losses ranging between 17.6-99.4 % depending upon the disease-causing factors. ToLCNDV-ES and ToLCNDV-OM are the most devastating strains of this virus. This comprehensive review will provide basic information on the characteristic features of ToLCNDV. The evolutionary mechanism of this virus is studied to know about the strain’s evolution with the passage of time on different host plants cultivated in several regions of the world. This review also covers the genome characteristics, geographical distribution, host range, transmission methods, genetic diversity, different molecular & serological assays, yield losses, and the management of this virus.

Fluorescent dual-mode assay of plant viral disease with polymerase chain reaction amplification

Plant viral diseases pose serious risk to the quality and yield of different crops. Herein, we described a highly sensitive and accurate immunosensor for early diagnosis of plant viral disease by using dual-signal readout with polymerase chain reaction (PCR) amplification. The sensor utilizes 6-carboxyfluorescein group (FAM) and tetramethyl-6-carboxyrhodamine (TAMRA) labeled primers as signal probes and their fluorescence signals were effectively quenched by graphene oxide (GO). In the presence of target plant viral related nucleic acid, the cDNA template could initiate the formation of long duplex PCR products with multiple signal probes. Such duplex PCR products cannot be quenched with GO, resulting in an obvious fluorescence signal. The results showed that FAM and TAMRA signals were proportional to the logarithm of the target cDNA concentration in the range of 10 fM–100 pM. The detection limit for the target cDNA was 0.08 fM for FAM and 0.07 fM for TAMRA, respectively. The practical application of our proposed strategy was successfully demonstrated by detection of emerging tobacco mosaic virus (TMV) infections in tobacco samples collected in the field, illuminating the possibility of applying this sensing platform for early diagnosis of plant disease.

Crop production on the Chinese Loess Plateau under 1.5 and 2.0 °C global warming scenarios

Global warming is a crucial factor affecting crop production in ecologically vulnerable areas. Warming-induced changes in the yields of different crops could pose significant challenges to food security and sustainability assessment. In this study, the World Food Studies model and a remote sensing product assimilation algorithm were used to develop a spatially explicit crop assimilation model applicable to the Loess Plateau of China. The model was used to simulate potential changes in actual yields and yield gaps for winter wheat and maize under three typical climate scenarios (Representative Concentration Pathways (RCPs): RCP 2.6, RCP 4.5, and RCP 8.5) from 2016 to 2060. Average yields increased in both winter wheat (2.38 %–4.96 %) and maize (5.41 %–6.85 %), with maize (RCP 4.5 > RCP 8.5 > RCP 2.6) more adapted to climate warming than winter wheat (RCP 2.6 > RCP 8.5 > RCP 4.5) in terms of yield increase rate. The yield increase and yield gap for winter wheat decreased most significantly in RCP2.6 (−2.28 %). Maize yield did not exceed 80 % of the potential yield in any scenario. The average phenological periods for winter wheat and maize are predicted be 2–4 and 9–16 days earlier, respectively. Crop yields were negatively correlated with radiation and yield gaps were positively correlated with precipitation. Future climate change will likely cause dramatic interannual crop yield fluctuations. Winter wheat is predicted to experience yield stagnation after 2050, whereas maize production potential will increase briefly before experiencing a long-term decline in growth. The results of this multi-scenario simulation assessment of crop production provide scientific support for implementing climate-adapted crop management strategies and integrated dry-crop-irrigated agriculture to meet food security objectives in this ecologically fragile area. We recommend integrated management measures to ensure regional food security through crop variety improvement, irrigation regulation, and planting structure optimization.

DEPENDENCE OF PRODUCTIVITY OF AGRICULTURAL PRODUCTION IN UKRAINE ON CHANGES IN THERMAL REGIME

The dynamics of changes in the average annual air temperature in 24 regions of Ukraine in the period 2011 - 2020 is analyzed. The correlation between the yield of major crops and the average annual air temperature is studied. The regional features of this dependence are analyzed. The regions of the country are ranked according to the degree of correlation between the average annual temperature and crop yields.
 Agriculture is largely dependent on natural factors, the most important of which is the change in agro-climatic conditions due to modern climate change. The main manifestation of modern climate change is an increase in air temperature, and in Ukraine the temperature increase is much more intense than in most regions of the world. Given the significant contribution of the agricultural sector to the economy of Ukraine, the problem of the dependence of agricultural production on changes in the thermal regime is of particular relevance.
 The article discusses the impact of changes in the thermal regime on the territory of Ukraine on the productivity of major agricultural crops. The average annual air temperature is used as an indicator characterizing the thermal regime of the territory. The dynamics of the average annual temperature in twenty-four regions of Ukraine in the period from 2011 to 2020 is analyzed. In particular, the regions of the most intensive increase in temperature have been identified. The relationship between the average annual air temperature and the productivity of the main agricultural crops, which include potatoes, sunflowers, as well as cereals and legumes, vegetables, fruit and berries, has been studied. To identify the relationship between temperature and yield, the method of pair correlation was used. The calculations were carried out using a Microsoft Excel spreadsheet.
 The study revealed significant differences in the degree of dependence of the yield of different crops on temperature conditions. It has been proven that the nature of the influence of thermal conditions on yield can vary significantly depending on the type of crop. In particular, the current increase in temperature favorably affects the efficiency of growing cereals and legumes and, at the same time, leads to a significant decrease in potato yield. It is shown that the dependence of the yield of different crops on air temperature is characterized by significant territorial disproportions. Wherein, the regions with the highest indicators of correlation dependence are located mainly in the west and northwest of Ukraine.
 The regions of Ukraine were ranked in accordance with the total degree of correlation between the average annual air temperature and the yield of selected agricultural crops. When ranking regions according to the degree of influence of the thermal factor, the arithmetic mean of the absolute values ​​(modules) of the correlation coefficients was used. According to the ranking results, the regions were grouped. It has been proved that when analyzing territorial disproportions, it is necessary to take into account the differences in the agricultural specialization of the regions, since the specialization of crop production causes significant differences in the sown areas of crops with different dependence on thermal factors.
 Based on the study, we can conclude that the current change in the thermal regime already has a significant impact on the process of transformation of agriculture, which, in particular, is manifested in a change in the agricultural specialization of the regions. For example, in regions specializing in the cultivation of vegetable crops, an increase in air temperature leads to a decrease in the efficiency of agricultural production. In turn, the decrease in the efficiency of agricultural production leads to a decrease in the volume of production. At the same time, the increase in the thermal resources of Polesye makes it possible to grow sunflower and other heat-loving crops in this zone.
 The novelty of the study is to obtain a comprehensive assessment of the influence of the thermal factor on the yield of various crops. At the same time, it should be noted that the main result of the study is obtaining a numerical characteristic of the degree of correlation dependence, which allows analyzing the degree of dependence of different crops on temperature conditions, as well as identifying and analyzing territorial disproportions in the distribution of this dependence.
 Key words: yield, average annual air temperature, specialization of agriculture.

Plant growth promoting and antagonistic traits of bacteria isolated from forest soil samples.

Sustainability in agricultural systems without compromising the environmental quality and conservation is one of the major concerns of today's world. The excessive use of agrochemicals is posing serious threats to the environment. Therefore identification of efficient plant growth promoting (PGP) bacteria as an alternative to chemically synthesized fertilizers is of great interest. In the present investigation, forest soil samples collected were used for isolation of efficient plant growth promoting bacteria. Total of 14 bacteria were isolated, and tested for various PGP properties. Out of the 14 isolates, four isolates labelled as BKOU-1, BKOU-8, BKOU-13 and BKOU-14 showed significant plant growth promoting traits, hydrolytic enzyme production and effectively restricted the mycelial development of phyto-pathogenic fungi (Fusarium oxysporum and Macrophomina phaseolina). 16 S rRNA gene sequences of the bacterial isolates BKOU-1, BKOU-8, BKOU-13 and BKOU-14 were found to have maximum identity with Bacillus aerius, Bacillus infantis, Alcaligenes faecalis and Klebsiella Oxytoca respectively. All four bacterial isolates nucleotide sequences were submitted to GenBank and NCBI accession numbers were generated as follows: OL721916, OL721918, OL721919 and OL721926. According to the findings of the study, these PGPR could be employed as biofertilizers/biopesticides to boost crop yield of different crops in sustainable manner.

State and development of grain storage engineering and technologies in Ukraine

Topicality. These researches are due to the grain storage problem, the features of maize grain storage in metal silos under the various environmental factors, as well as more efficient using the material and technical facilities, including the grain storages of new generation. Purpose. To establish the types of grain storage facilities that are most appropriate for storing the yield of different crops, to improve metal silos and maize grain storage technologies. Materials and Methods. During experiments on maize grain storage, we used the metal silo equipped with a system of sensors to measure the temperature in different places of grain heap. We studied two models of grain storages, such as a standard construction (control) and an experimental one thermal isolated with a polyurethane layer. During the storage experiment, grain quality was monitored on grain moisture content, dockage, damage and germination. Results. Different types of grain storage facilities storing main volume of grain harvest were characterized; the technical, economic and technological advantages and disadvantages of grain storage were highlighted; directions for further development are outlined. The features of maize grain storage in the metal silos under influence of external meteorological conditions for 60 day were established. Temperature fluctuations were 7.1–13 °С in grain storage with thermal insulation, 4.5–25.9 °С – without insulation. As a result of significant temperature fluctuations, the grain was moistened by 2.2 %, its acidity increased by 1 degree, germination decreased by 7 %. At the stage of preparation for storage, maize grain should be cleaned to purity of 93–97 % by removing grain impurities. An effective method for this is fractional separation of grain. Conclusions. Thermal insulation of metal silos significantly reduces the negative impact of fluctuations in ambient air temperature, stabilizes the storage mode, and ensures high quality maize grain. The stability of grain during storage increases in the case of selection from it a fraction of grain of small, unfilled, with a low 1000 grain weight. Key words: types of grain storage facilities, metal silo, thermal insulation, maize, quality, cleaning grain before storage

Molecular identification of root-lesion nematodes, Pratylenchus spp. in agricultural crops from Costa Rica

Introduction. The root-lesion nematodes, Pratylenchus spp., have a wide host range and reduce the yield of different crops. Information on the diversity of Pratylenchus species is scarce in Costa Rica. Objective. To identify the Pratylenchus species associated with 12 crops based on the D3 region of the 28S rDNA gene. Materials and methods. During 2013 to 2015, root samples were collected in Alajuela, Cartago, Guanacaste, Heredia, and San José in crops of rice (Oryza sativa), black pepper (Piper nigrum), sugarcane (Saccharum officinarum), aster (Aster sp.), coffee (Coffea arabica), banana (Musa paradisiaca), lily (Lilium sp.), gypsophila (Gypsophila sp.), onion (Allium cepa), potato (Solanum tuberosum), strawberry (Fragaria x ananassa), and leather-leaf fern (Rumohra adiantiformis). The D3 region of the 28S rDNA gene from each population was amplified and sequenced. A GenBank Blast Search was performed for each sequence. The phylogenetic relationships were established by Bayesian Inference. Results. Blast Search indicated the presence of P. pseudocoffeae in aster, P. brachyurus in black pepper, P. crenatus in onion and potato, P. hippeastri and P. gutierrezi in sugarcane and coffee, respectively. Pratylenchus bolivianus in leather-leaf fern and potato, P. penetrans in onion, strawberry, gypsophila, and lily, P. zeae in rice and sugarcane, while P. speijeri in banana. The phylogenetic analysis corroborated the Pratylenchus species identity with exceptions of sequences from 1) banana, grouped to P. coffeae complex group, 2) sugar cane, grouped to P. hippeastri complex group 3) onion and potato were related with P. crenatus, in an independent group, and 4) leather-leaf fern and potato were grouped with P. bolivianus with low resolution. Conclusions. Nine genetic groups of Pratylenchus were found, some of those should be verified with other molecular markers to get a conclusive identification.

Fruit Yield of Tabasco Pepper Under Water Deficit with Magnetically Treated Water

Magnetically treated water (MTW) has been used to promote biomass yield in different crops. Tabasco pepper is a high water-demanding crop often cultivated in areas with limited water supply. This study aims to evaluate the effect of MTW on the physiology and biomass yield of Tabasco pepper under water deficit. The experiment consisted of two groups of randomly distributed plants receiving normal water and MTW at two irrigation levels (100 % and 50 % of field capacity, FC) during the whole life cycle under mesh-house. Water was magnetically treated with a commercial irrigation device. Fruit biomass, photosynthesis, water potential, and leaf tissue status were measured. Fruit yield showed a non-significant increase in plants with MTW at both irrigation levels, although large- and medium-sized effects were detected regarding dry weight and fruits per plant (> 16 % increase). Concerning photosynthesis parameters, only quantum yield significantly increased, even though net assimilation and stomatal conductance exhibited a 17 % and 28 % increment, respectively. At 50 % FC, photosynthetic parameters and leaf water potential were severely impaired no matter the treatment used, but surprisingly, relative water content and electrolyte leakage in leaves were not significantly affected. Despite the minor physiological effects of MTW observed in this study, the size effect on fruit yield was noticeable at the end of the experiments. Hence, the application of MTW could help improve water use efficiency in Tabasco pepper in combination with reduced irrigation strategies.

Differential regulation of flower transpiration during abiotic stress in annual plants.

Summary Heat waves occurring during droughts can have a devastating impact on yield, especially if they happen during the flowering and seed set stages of the crop cycle. Global warming and climate change are driving an alarming increase in the frequency and intensity of combined drought and heat stress episodes, critically threatening global food security.Because high temperature is detrimental to reproductive processes, essential for plant yield, we measured the inner temperature, transpiration, sepal stomatal aperture, hormone concentrations and transcriptomic response of closed soybean flowers developing on plants subjected to a combination of drought and heat stress.Here, we report that, during a combination of drought and heat stress, soybean plants prioritize transpiration through flowers over transpiration through leaves by opening their flower stomata, while keeping their leaf stomata closed. This acclimation strategy, termed ‘differential transpiration’, lowers flower inner temperature by about 2–3°C, protecting reproductive processes at the expense of vegetative tissues.Manipulating stomatal regulation, stomatal size and/or stomatal density of flowers could serve as a viable strategy to enhance the yield of different crops and mitigate some of the current and future impacts of global warming and climate change on agriculture.

Dietary Fats, Human Nutrition and the Environment: Balance and Sustainability.

Dietary fats are essential ingredients of a healthy diet. Their production, however, impacts the environment and its capacity to sustain us. Growing knowledge across multiple disciplines improves our understanding of links between food, health and sustainability, but increases apparent complexity. Whereas past dietary guidelines placed limits on total fat intake especially saturated fats, recent studies indicate more complex links with health. Guidelines differ between regions of general poverty and malnutrition and those where obesity is a growing problem. Optimization of production to benefit health and environmental outcomes is hindered by limited data and shared societal goals. We lack a detailed overview of where fats are being produced, and their environmental impacts. Furthermore, the yields of different crops, for producing oils or feeding animals, and the associated land needs for meeting oil demands, differ greatly. To illuminate these matters, we review current discourse about the nutritional aspects of edible fats, summarize the inferred environmental implications of their production and identify knowledge gaps.

Reconnoitring the Relationship between Farm Size and Productivity and Economies of Scale in Agriculture in Eastern Uttar Pradesh

An attempt was made to understand the recurrent debate about the relationship between returns to cultivation per hectare and size-class of land cultivated in eastern Uttar Pradesh using primary data collected from the five districts from each agro-climatic zones of the eastern region. The research showed the statistical validity of the farm size and crop productivity, which was a crucial exploration. The analysis was done separately for the relationship to the total value of agriculture output and yield of different crops grown in the study area. The empirical evidence proved the hypothesis that there was a negative association between land size and crop yield. The study further argued that the efficiency of the small-land holders must be taken with a pinch of salt because their low absolute returns bring into focus the question of their livelihood sustainability which was further aggravated on account of higher unit costs incurred. The first exercise in a series of proposed explorations into disaggregated analyses across the State of Uttar Pradesh and for specific crops opens the classic debate on farm size and productivity in the 21st century.

TAX INCENTIVES TO MANAGE LAND AS A NATURAL ASSET

Topicality. Successful economic development of agriculture is one of the components of Ukraine's sustainable development. But this development very often leads to changes in natural and climatic conditions and to increased risks for doing business. Agricultural land is a natural asset and it should be taken into account that the change oflandscapes from natural vegetation to any other use can lead to loss, degradation, and fragmentation of the environment, all of which can have devastating consequences for biodiversity as a source of ecosystem services. Therefore, it is important to find ways to rationally manage the land.Aim and tasks. The purpose of our study was to substantiate the relevance of taxes for the management and rational use of land as a natural asset. As a tool, we consider a tax on crop rotation, which leads to a decrease in soil fertility and the release of carbon from dying plant residues. Crop rotation planning will help reprioritize crop selection, increase fertility and reduce carbon emissions.Research results. The main component of the sustainable development of the agricultural sector is soil fertility. At the same time, land use and agriculture are the main natural agents for reducing air pollution. Today, agriculture accounts for about 20% of greenhouse gas emissions, and humus losses range from 19% to 22% in different natural areas. Considering agricultural land as a natural asset, it should be taken into account that their irrational use leads to a change in natural and climatic conditions and an increase in risks for doing business. We have proposed to introduce carbon crop rotations as a tool for soil quality management. In our opinion, this should contribute to a change in priorities in the choice of agricultural crops, and as a result, an increase in fertility and an increase in carbon sequestration. To stimulate agricultural enterprises, we consider it expedient to introduce a tax on crop rotation. To substantiate this idea, we have created a model for the dependence of CO2 absorption/emission on the yield of various crops and a decision-making model for planning the costs of an agricultural enterprise.Conclusion. We have conducted a study of the relationship between the yield of various crops and the absorption/release of carbon dioxide. We put forward a hypothesis: there is a certain relationship between the yield of different crops and the balance of absorption/release of CO2. We have studied this connection. The model of dependence of CO2 uptake/emission on the yield of different crops shows that the ability to release carbon by plant residues of different agricultural crops has both a direct and inverse relationship with the yield of various crops. We have developed a decision-making model for planning the costs of an enterprise, subject to planning for environmental risks or paying a tax on carbon crop rotations. Thus, the problems of land use as a natural asset in agriculture can be solved by: the introduction of carbon crop rotations, which should help change priorities in the choice of agricultural crops, and the introduction of a balanced and evidence-based approach to the development and implementation of environmental taxes.

Effects of irrigation-fertilization-tillage on nutrient loading and crop yield in Ulansuhai watershed based on improved SWAT model

不合理的灌溉、施肥和耕作是导致乌梁素海流域农业面源污染的主要根源，乌梁素海作为我国北方地区重要的生态安全屏障，多年来面临着湖泊水环境污染、水生态退化等问题，科学开展湖泊水环境综合治理首先要解决流域内农业面源污染问题. 研究通过修改土壤水平衡、溶质平衡、地下水平衡和作物生长等模块对SWAT 2012原始版本进行改进，并采用改进的SWAT模型构建了乌梁素海流域分布式水文模型，利用实测径流、硝态氮与总磷排放量、地下水埋深以及作物产量校正和验证模型. 基于现状情景，以玉米、葵花和小麦3种主要作物为研究对象，设置了削减灌水量、施肥量及调整耕作方式3种农田管理情景. 基于改进SWAT模型不同情景的模拟结果，计算分析各管理情景下的硝态氮与总磷负荷及对各作物产量的影响. 结果表明，改进SWAT模型具有良好的模拟效果. 不同作物削减5%夏灌水量增产最多达8.41%~10.32%，削减10%秋浇水量均明显减少硝态氮和总磷负荷. 不同作物营养物负荷均随着氮磷施肥削减比例的增大呈现逐渐降低的趋势，但下降曲线逐渐趋于平缓; 各作物产量随氮磷施肥削减比例的增加呈先增加后减少的趋势，其中玉米、小麦氮磷施肥削减比例达20%时产量开始下降，葵花氮磷施肥削减比例达25%时产量开始下降. 不同作物营养物负荷与小麦产量均随耕作方式混合深度与混合效率参数的增大逐渐减小，而玉米和葵花产量则随耕作参数增大逐渐增加. 综合分析，削减5%夏灌水量+削减20%氮磷施肥比例+模板犁耕作组合玉米产量增幅最大达36.5%;削减10%秋浇水量+削减25%氮磷施肥比例+模板犁耕作组合葵花硝态氮负荷降幅最大达42.1%;削减5%夏灌水量+削减20%氮磷施肥比例+免耕组合小麦产量增幅最大达29.1%;而削减5%秋浇水量+削减20%氮磷施肥比例+常规春耕组合小麦硝态氮负荷减少最大达27.2%，总磷负荷减少最大达18.5%. 本研究可为降低流域内面源污染、提高作物产量及减少乌梁素海营养物入湖负荷农业管理措施的实施提供理论依据.;Irrational irrigation, fertilization and farming are the main causes of agricultural non-point source pollution in Ulansuhai watershed. As an important ecological security barrier in northern China, Lake Ulansuhai has been facing problems, such as lake water environment pollution and water ecological degradation. To achieve the integrated management of lake water environment, agricultural non-point source pollution in the watershed must be controlled. The study improved the original version of SWAT 2012 by modifying the modules of soil water balance, solute balance, groundwater balance, and plant growth. A distributed hydrological model of Ulansuhai watershed was constructed with the improved SWAT model, which was calibrated and validated with measured runoff, nitrate nitrogen (NN), total phosphorus (TP) emissions, groundwater depth and crop yield. Three scenarios including reduced amount of irrigation, fertilization, and adjusted farming mode based on the current situation were applied on three main crops (corn, sunflower and wheat). NN and TP loadings and their effects on the crop yields under different management scenarios were simulated using the improved SWAT model. The results showed that the improved SWAT model has a good simulation fitting. For different crops, reducing the irrigation amount by 5% in summer can increase production by up to 8.41%-10.32%, and reducing 10% irrigation in autumn will significantly reduce the NN and TP loadings. The nutrient load of different crops showed a decreasing trend with an increasing reduction ratio of nitrogen and phosphorus fertilization (NPF), but the declining rate gradually became smaller. The yields of different crops increased first and then decreased with the ratio of NPF increase. When the ratio of NPF reduction reached 20%, the yield of corn and wheat began to decline, and when it reached 25% the yield of sunflower began to decline. The nutrient loads and wheat yield of different crops gradually decreased with an increase of the mixing depth and efficiency of the tillage mode, while the yield of corn and sunflower gradually increased with the tillage parameters. If combining cutting 5% of summer irrigation, reducing 20% NPF amount, and the template plowing combination, corn yield could increase by 36.5%. If cutting 10% of autumn watering, reducing 25% NPF, the template plowing combination, sunflower nitrate nitrogen load could reduce by 42.1%. If cutting 5% of summer irrigation, 20% reduction NPF, and no-tillage combination, wheat yield could increase by 29.1%. However, cutting 5% of autumn watering, 20% reduction NPF and conventional spring ploughing combination, NN loading of wheat farming could reduce by up to 27.2%, and TP loading could reduce by up to 18.5%. This research can provide a scientific basis for the implementation of agricultural management measures to reduce non-point source pollution, increase crop yields in Ulansuhai watershed and reduce the nutrients loads in Lake Ulansuhai.

Super absorbent polymer application under suboptimal environments: implications and challenges for marginal lands and abiotic stresses

World population is increasing at an alarming rate, and crop cultivation on marginal lands has emerged as an alternate option to feed the burgeoning population. However, marginal lands are characterized by poor soil health and other undesirable characteristics resulting in low crop production and less economic returns. Interest in the application of superabsorbent polymers (SAPs) for marginal lands has been increasing. The SAPs application increases the germination percentage, seedling growth, and grain yield of different crops. Being hydrophilic in nature, SAPs can absorb and retain a huge quantity of water, and thereby enhance the water use efficiency in crops. In addition, SAPs application also showed a positive influence on soil physico-chemical properties and enhanced the retention of water and nutrients. Marginal lands are frequently subjected to abiotic stresses such as drought, heavy metals, and salinity. The application of SAPs serves as a buffer against these abiotic stresses and reduces the risk of plant damage and hence crop failure. Over the past decade, focused efforts have been undertaken on SAPs application on arable lands, especially in arid regions. However, understanding about SAPs application on marginal lands is not well understood. The present review critically discusses the potential of SAPs application to enhance the productivity of marginal lands with a major focus on crop performance under different stresses. Current challenges hindering the wide application of SAPs are also discussed.

Management of white grubs through a novel technology in Uttarakhand hills of North-West Himalayas

White grubs, a group of destructive insect pests of polyphagous nature, cause severe damage to crop plants in hill ecosystem. The grubs with subterranean habitat feed extensively on the roots and the adults defoliate the plants. A two-pronged strategy involving an efficient, light weight, eco-friendly, low cost, light-based insect trap for capturing the adults and a novel entomopathogen, Bacillus cereus strain WGPSB-2 for the management of grubs was developed. Large scale deployment of the above technology was done on community basis in 18 villages of low, mid and high-altitude areas including two experimental farms of Uttarakhand hills. Three years experimentation revealed drastic reduction in beetle population to the tune of 75.8, 78.5 and 80.5 per cent in low, mid and high-altitude villages respectively. A significant reduction of the grub population was recorded in the range of 87.8 to 95.7 per cent in three years across the different villages. As a result of reduction in grub population, per cent increase in yield of different crops was recorded from 23.8 to 187.9 per cent in different villages and experimental farms of low, mid and high altitudes. The technology is thus, capable of managing white grubs at different altitudes of hills in general and North Western Himalayas in particular.