Crop management options to reduce nitrogen pollution in Liangzihu lake basin, Central China

In Central China, high mineral nitrogen (N) application rates lead to low N recovery and high N losses. Large amounts of the nitrate-N leached from agricultural soil end up in aquatic ecosystems, which negatively affects both ecosystem and human health. Such effects are particularly pronounced in the Liangzihu Lake basin, Central China, where application of mineral N to the predominating maize-wheat rotation systems on coarse-textured soils can exceed 300 kg ha-1. We hypothesize that improved crop management can reduce the current nitrate-N pollution while enhancing system performance. The present study initially identified the main drivers of excessive N use by household surveys. Subsequent field experiments between 2012 and 2013 evaluated the effects of modified fertilizer-N management and the use of N-catching cover crops on soil-N dynamics, N-use efficiency, yield of maize and wheat, and nitrate-N leaching. Finally, the field trial data were used to parameterize the Environmental Policy Integrated Climate (EPIC) model to estimate N leaching losses under current and alternative crop and N management. Current N application rates average 229 kg N ha-1 season-1, which is higher than the cereal crop requirements of 150-180 kg N ha-1. The main reasons for the excessive use of mineral N are related to low farmland productivity (r = -0.184, p = 0.003), small farm size (r = -0.168, p = 0.006), a high share of off-farm income (coefficient = 25.94, p = 0.003), and a low education level of the household head (coefficient = -11.20, p = 0.034). The field experiment could show that cultivating a cover crop combined with a reduced application rate (290 kg N ha-1 in 3 splits) and multiple splitting of mineral N fertilizer can achieve similar yields (6.4-6.9 Mg ha-1) to those obtained with current management (470 kg N ha-1 in 2 splits). In addition, this alternative crop and fertilizer management increased the agronomic N-use efficiency by 7 kg grain kg-1 N applied in both wheat and maize, and enhanced the N-fertilizer recovery by 15% in wheat and 20% in maize. In addition, nitrate-N leaching was reduced by 15 kg N ha-1 in both the first-year maize and wheat crops. Once calibrated with the data from the field experiment, the EPIC model was able to predict crop biomass and the soil water content under moderate (long-term mean) climate conditions with a determination coefficient higher than 0.5 and a model bias of less than 3%. However, the model underestimated the soil water content in the drought seasons with a bias of >36%. Moreover, it tended to slightly overestimate nitrate-N leaching with 13-181 kg N ha-1 for the entire experimental period and in both 1 m and 1.8 m soil depths. It is concluded that (1) the current N application rate in the study area is excessive because of insufficient awareness and the easy and low-cost availability of mineral-N fertilizers, (2) the currently high N losses from crop fields can be substantially reduced by reducing application rates and by replacing bare fallow periods with legume cover crops without negative trade-offs in crop yields, and (3) the calibrated EPIC model can be used to predict the aboveground crop biomass and the soil water content, but it tends to overestimate nitrate-N leaching. Consequently, there is a need to inform farmers about the negative effects of excessive N use, popularize alternative agronomic management options, and adapt the existing EPIC model to improve the prediction of nitrate pollution in Central China

Agroeconomic viability of grape-common bean intercropping

The intercropping of agricultural crops aims to increase the profitability and the sustainability of the production systems. The objective of this study was to evaluate the agroeconomic viability of the intercropping of grape with common bean grown at different planting densities and weed management. The experimental design adopted was randomized blocks in a split-plot scheme. Treatments in the plots consisted of weed managements, mowing and chemical, and, in the subplot, the intercropping of grape with 0, 4, 8 and 12 common bean plants/linear meter. Grape-common bean intercropping and weed management did not influence the performance of grape crop. Regarding the agronomic characteristics of common bean, the highest values of plant height and yield were found with 8 and 12 plants/linear meter. Plant dry mass was higher when the common bean was intercropped with 4 plants, compared to 12 plants. For the agroeconomic indicators, land use efficiency index, monetary advantage and corrected monetary advantage, the best results were found with the intercropping with 8 bean plants, while the best results for gross income and net income were found under intercropping with 12 plants. Chemical and mowing weed managements can be recommended for the grape-common bean intercropping because they are efficient and do not affect the performance of the intercropped crops. The intercropping of grape with common bean is feasible because the gross and net income increase up to the density of 12 plants of common bean/linear meter and the intercropping with 8 plants/linear meter resulted in higher values of land use efficiency and monetary advantage.The intercropping of agricultural crops aims to increase the profitability and the sustainability of the production systems. The objective of this study was to evaluate the agroeconomic viability of the intercropping of grape with common bean grown at different planting densities and weed management. The experimental design adopted was randomized blocks in a split-plot scheme. Treatments in the plots consisted of weed managements, mowing and chemical, and, in the subplot, the intercropping of grape with 0, 4, 8 and 12 common bean plants/linear meter. Grape-common bean intercropping and weed management did not influence the performance of grape crop. Regarding the agronomic characteristics of common bean, the highest values of plant height and yield were found with 8 and 12 plants/linear meter. Plant dry mass was higher when the common bean was intercropped with 4 plants, compared to 12 plants. For the agroeconomic indicators, land use efficiency index, monetary advantage and corrected monetary advantage, the best results were found with the intercropping with 8 bean plants, while the best results for gross income and net income were found under intercropping with 12 plants. Chemical and mowing weed managements can be recommended for the grape-common bean intercropping because they are efficient and do not affect the performance of the intercropped crops. The intercropping of grape with common bean is feasible because the gross and net income increase up to the density of 12 plants of common bean/linear meter and the intercropping with 8 plants/linear meter resulted in higher values of land use efficiency and monetary advantage

Nitrogen Surplus Benchmarks for Controlling N Pollution in the Main Cropping Systems of China

This study was financially supported by National Key Research and Development Project of China (2017YFD0200105), China−UK PhD Placement Programme funded by CSC (201603780082), and contributes to “N-Circle” and “CINAg” projects funded by the Newton Fund via UK BBSRC/NERC (grants BB/N013484/1 and BB/N013468/1, respectively).Peer reviewedPostprintPostprin

Cactus pear (Opuntia ficus-indica) productivity, proximal composition and soil parameters as affected by planting time and agronomic management in a semi-arid region of india

Study of appropriate planting time and response to agronomic management practices is imperative for the newly introduced cactus pear (Opuntia ficus-indica (L.) Mill.) into a semi-arid region of India. Responses of cactus pear to agronomic practices (planting time and irrigation and fertilizer application) were evaluated to determine the potential for fodder production and livestock feed in a semi-arid environment of India. We assessed four planting times (February, March, July and October) and two agronomic managements (with and without irrigation and fertilizer application) during 2016–2020 at Jhansi, India. Cactus pear establishment and growth improved with planting time in July and October due to favorable soil moisture and congenial temperature. However, plant height (19 cm) and cladode weight (118 g) were greater in July than in October planting. Nutrient uptake and crude protein contents, however, were higher for the earlier plantings of February and April compared to June and October. Irrigation and nutrients application had little effect on the cactus pear plant growth, except on plant width and cladode length and width. Cactus pear can be planted during July in moderately fertile soils without any agronomic intervention in semi-arid situations of India and has potential as an effective alternative source of forage for livestock during the summer months

Chickpea production in response to fertilization with zinc and doses of phosphorus

Chickpea cultivation in Brazil has not yet been consolidated, and studies aiming at the adequate nutritional management for this crop are necessary. This work aimed to evaluate the production of chickpea plants (cultivar BRS Aleppo) subjected to fertilization with zinc and P doses. The experimental was completely randomized, with four replications, in a 3 x 5 factorial scheme, corresponding to three fertilization treatments with Zn (without Zn addition; 50% of Zn applied at sowing, via soil + 50% applied at flowering, via leaves; and 100% applied at sowing, via soil) and five doses of phosphorus (0, 60, 120, 180, and 240 kg ha-1 of P2O5). The 100-grain mass (M100), pod mass (MV), number of pods (NV), number of grains (NG), total grain mass (MGT), yield (PROD), dry matter of the shoot part (MSPA) and plant residues (MSRV), and agronomic efficiency (EA) were characterized. There was an isolated effect of the P doses on the M100, MGT, PROD, MSPA, and MSRV characteristics. The application of 240 kg ha-1 resulted in an increase in the production components and a maximum yield of 3,018 kg ha-1, indicating the need to adopt higher doses of P2O5 to increase chickpea production in tropical soils. However, the highest agronomic efficiency was obtained after the application of 60 kg ha-1 of P2O5, along with Zn at sowing.Chickpea cultivation in Brazil has not yet been consolidated, and studies aiming at the adequate nutritional management for this crop are necessary. This work aimed to evaluate the production of chickpea plants (cultivar BRS Aleppo) subjected to fertilization with zinc and P doses. The experimental was completely randomized, with four replications, in a 3 x 5 factorial scheme, corresponding to three fertilization treatments with Zn (without Zn addition; 50% of Zn applied at sowing, via soil + 50% applied at flowering, via leaves; and 100% applied at sowing, via soil) and five doses of phosphorus (0, 60, 120, 180, and 240 kg ha-1 of P2O5). The 100-grain mass (M100), pod mass (MV), number of pods (NV), number of grains (NG), total grain mass (MGT), yield (PROD), dry matter of the shoot part (MSPA) and plant residues (MSRV), and agronomic efficiency (EA) were characterized. There was an isolated effect of the P doses on the M100, MGT, PROD, MSPA, and MSRV characteristics. The application of 240 kg ha-1 resulted in an increase in the production components and a maximum yield of 3,018 kg ha-1, indicating the need to adopt higher doses of P2O5 to increase chickpea production in tropical soils. However, the highest agronomic efficiency was obtained after the application of 60 kg ha-1 of P2O5, along with Zn at sowing

Portable chlorophyll meter in monitoring and management of nitrogen in common bean cultivars

More sustainable practices involving biological nitrogen fixation (BNF) and the use of portable chlorophyll meter in fertilization management are promising to increase nitrogen (N) use efficiency in the common bean crop. This study aimed to monitor N managements using a portable chlorophyll meter and its effects on agronomic attributes of Carioca-type common bean cultivars with indeterminate and determinate growth habits (‘IPR Campos Gerais’ and ‘IAC Imperador’). The experiment was carried out in a randomized block design (RBD), in a 2 × 9 factorial scheme, with four replicates. The first factor consisted of the cultivars and the second factor of the N management. The data were subjected to analysis of variance by F test and, when necessary, the means were grouped by the Scott-Knott test at 5% probability level. The use of portable chlorophyll meter is a viable alternative for N monitoring and management in common bean, allowing the reduction of top-dressing N application, regardless of the cultivar used. Highlights The use of portable chlorophyll meter is a viable alternative for nitrogen monitoring and management in common bean. Management with chlorophyll meter reduced the need for chemical fertilizer application, saving 105 kg ha-1 of urea. Further studies are needed to better understand this technology under conditions with different genotypes, soils and production systems.More sustainable practices involving biological nitrogen fixation (BNF) and the use of portable chlorophyll meter in fertilization management are promising to increase nitrogen (N) use efficiency in the common bean crop. This study aimed to monitor N managements using a portable chlorophyll meter and its effects on agronomic attributes of Carioca-type common bean cultivars with indeterminate and determinate growth habits (‘IPR Campos Gerais’ and ‘IAC Imperador’). The experiment was carried out in a randomized block design (RBD), in a 2 × 9 factorial scheme, with four replicates. The first factor consisted of the cultivars and the second factor of the N management. The data were subjected to analysis of variance by F test and, when necessary, the means were grouped by the Scott-Knott test at 5% probability level. The use of portable chlorophyll meter is a viable alternative for N monitoring and management in common bean, allowing the reduction of top-dressing N application, regardless of the cultivar used. Highlights The use of portable chlorophyll meter is a viable alternative for nitrogen monitoring and management in common bean. Management with chlorophyll meter reduced the need for chemical fertilizer application, saving 105 kg ha-1 of urea. Further studies are needed to better understand this technology under conditions with different genotypes, soils and production systems

Effect of Integrated Soil Fertility Management on Crop Production: A Review

Maintaining soil fertility is one of the main factors affecting the sustainability of food production. Indiscriminate use of chemical fertilizers, coupled with neglected maintenance of the vitality of the soil and the use of destructive methods have caused loss or destruction of the existing population of soil organisms. The use of chemical fertilizer, organic fertilizer or bio fertilizer has its advantages and disadvantages in the context of nutrient supply, crop growth and environmental quality. The advantages need to be integrated in order to make optimum use of each type of fertilizer and achieve balanced nutrient management for crop growth. This review study showed that balanced fertilization using both organic and chemical fertilizers is important for maintenance of soil organic matter (OM) content and long-term soil productivity in the tropics where soil OM content is low. The basic concept underlying the ISFM is the adjustment of soil fertility and plant nutrient supply to an optimum level for sustaining desired crop productivity through optimization of the benefits from all possible sources of plant nutrients in an integrated manner. Therefore, increased attention should be being paid to developing an integrated soil fertility management that maintains or enhances soil productivity through balanced use of all sources of nutrients, including chemical fertilizers, organic fertilizers and bio fertilizers. Keywords: Chemical Fertilizer, Organic Fertilizer, Integrated Soil Fertility Management DOI: 10.7176/JBAH/9-8-01 Publication date: April 30th 201

The Effects of Biochar and Nitrogen Stabilizers Application on Forage Crop Growth, Greenhouse Gas Emission and Soil Quality

ABSTRACT Forage systems are important for animal production. Nitrogen fertilization and herbicides use has led to a significant increase in forage production. Therefore, this study aimed to investigate the effects of biochar and N-(n-butyl) thiophosphoric triamide + dicyandiamide (NBPT+DCD) application on manure and urea fertilized soil by focusing on nitrogen fertilizer efficiency use, greenhouse gases emissions, microbial community, soil aggregate stability, and organic carbon functional groups. In addition, herbicides effect on greenhouse gases emission was assessed. Biochar and NBPT+DCD increased nitrogen use efficiency of both fertilizers managements and reduced the N2O emissions following manure fertilization. However, NBPT+DCD was a better tool to enhance the use efficiency of both fertilizers and to reduce the N2O emission of urea fertilization. The use of manure as nitrogen fertilizer and biochar appeared to increase microbial biomass, bacteria and fungi relative abundances in the soil. In contrast, the use of NBPT+DCD presented to be detrimental to microbial biomass, especially for bacteria and saprophytic fungi. Manure fertilization and biochar application increased soil aggregation and stability. Manure application contributed to more aliphatic components (non-polar) and polysaccharides (binding agent) of soil organic matter in larger aggregates. On the other hand, biochar application increased carboxylic functional groups in smaller aggregates. Indaziflam increased CH4 emissions from a pasture soil, while nicosulfuron plus metsulfuron-methyl and oxadiazon reduced N2O emission. These findings will improve sustainable farming practices on forage production systems in southern region of United States

Aplicação exógena de tiamina ameniza os efeitos da baixa saturação de bases do solo sobre plantas de pimentão?

O uso intensivo do solo para a produção de hortaliças resulta em elevada degradação do solo e da área de cultivo. A utilização de técnicas e recursos que viabilizem a produção sob condições desfavoráveis pode ser decisiva para agricultura. Desta maneira, o objetivo deste trabalho foi avaliar os efeitos isolados e conjuntos da correção do solo e da aplicação de tiamina sobre o desenvolvimento das plantas de pimentão. Os tratamentos foram compostos por três diferentes saturações de base do solo (36, 60 e 80%), combinadas à aplicação de tiamina via foliar (com e sem) na concentração de 100 mg L-1. Verificou-se que a tiamina ameniza os efeitos da baixa saturação por base do solo sobre as características fisiológicas das plantas de pimentão. Os incrementos relativos à eficiência do uso da água e da eficiência instantânea de carboxilação, possibilitaram maior desenvolvimento das plantas tratadas com tiamina. Em complemento, a aplicação da tiamina é vantajosa para casos em que o plantio é realizado em condições de baixa saturação por bases, seguida da oferta adequada de nutrientes ou sistemas em que há parcial ou total correção das características químicas do solo, promovendo o desenvolvimento das plantas e aumento da atividade fisiológica.The intensive use of land to produce vegetables results in high soil degradation and cultivated area. The use of techniques and resources that make production possible under unfavorable conditions can be decisive for agriculture. Thus, this study aimed to evaluate the isolated and joint effects of liming and thiamine application on the development of bell pepper plants. The treatments consisted of three different soil base saturation (36, 60, and 80%), combined with foliar application of thiamine (with and without) at a concentration of 100 mg L-1. It was found that thiamine mitigates the effects of low base saturation on the physiological traits of bell pepper plants. The increments related to the water use efficiency and instantaneous carboxylation efficiency allowed greater development of plants treated with thiamine. In addition, the application of thiamine is advantageous in cases where planting is carried out under conditions of low base saturation, followed by an adequate supply of nutrients or systems in which there is a partial or total correction of the soil chemical characteristics, promoting the development of plants and increased physiological activity