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1.
PLoS One ; 15(9): e0237460, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32911506

RESUMO

Infection of wheat by Fusarium species can lead to Fusarium Head Blight (FHB) and mycotoxin contamination, thereby reducing food quality and food safety, and leading to economic losses. Agronomic management through the implementation of various pre-harvest measures can reduce the probability of Fusarium spp. infection in the wheat field. To design interventions that could stimulate wheat farmers to (further) improve their agronomic management to reduce FHB, it is key to understand farmers' behaviour towards adapting their management. The aim of this paper was to understand the intention, underlying behavioural constructs, and beliefs of Dutch wheat farmers to adapt their agronomic management to reduce FHB and mycotoxin contamination in wheat, applying the Theory of Planned Behaviour (TPB). Data were collected from 100 Dutch wheat farmers via a questionnaire. The standard TPB analysis was extended with an assessment of the robustness of the belief results to account for the statistical validity of the analysis on TPB beliefs (i.e. to address the so-called expectancy-value muddle). Forty-six percent of the farmers had a positive intention to change their management in the next 5 years. The two behavioural constructs significantly related to this intention were attitude and social norm, whereas association with the perceived behavioural control construct was insignificant indicating that farmers did not perceive any barriers to change their behaviour. Relevant attitudinal beliefs indicated specific attributes of wheat, namely yield, quality and safety (lower mycotoxin contamination). This indicates that strengthening these beliefs-by demonstrating that a change in management will result in a higher yield and quality and lower mycotoxin levels-will result in a stronger attitude and, subsequently, a higher intention to change management. Interventions to strengthen these beliefs should preferably go by the most important referents for social norms, which were the buyers and the farmer cooperatives in this study.


Assuntos
Produção Agrícola/métodos , Fusarium/isolamento & purificação , Doenças das Plantas/prevenção & controle , Triticum/microbiologia , Agricultura/métodos , Controle Comportamental , Fazendeiros , Qualidade dos Alimentos , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Intenção , Doenças das Plantas/microbiologia , Normas Sociais , Inquéritos e Questionários
2.
Ecotoxicol Environ Saf ; 202: 110950, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32800226

RESUMO

Human exposure to methylmercury (MeHg) through rice consumption is raising health concerns. It has long been recognized that MeHg found in rice grain predominately originated from paddy soil. Anaerobic conditions in paddy fields promote Hg methylation, potentially leading to high MeHg concentrations in rice grain. Understanding the transformation and migration of Hg in the rice paddy system, as well as the effects of farming activities, are keys to assessing risks and developing potential mitigation strategies. Therefore, this review examines the current state of knowledge on: 1) sources of Hg in paddy fields; 2) how MeHg and inorganic Hg (IHg) are transformed (including abiotic and biotic processes); 3) how IHg and MeHg enter and translocate in rice plants; and 4) how regular farming activities (including the application of fertilizer, cultivation methods, choice of cultivar), affect Hg cycling in the paddy field system. Current issues and controversies on Hg transformation and migration in the paddy field system are also discussed.


Assuntos
Produção Agrícola/métodos , Monitoramento Ambiental/métodos , Mercúrio/análise , Compostos de Metilmercúrio/análise , Oryza/efeitos dos fármacos , Poluentes do Solo/análise , Fertilizantes/análise , Humanos , Mercúrio/metabolismo , Compostos de Metilmercúrio/metabolismo , Oryza/crescimento & desenvolvimento , Oryza/metabolismo , Solo/química , Poluentes do Solo/metabolismo
3.
PLoS One ; 15(8): e0237245, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32780782

RESUMO

Straw mulching has been widely adopted in dryland cropping but its effect on soil respiration and microbial communities under warming are not well understood. Soil samples were collected from a corn field with straw mulching (SM) for nine years and without straw mulching (CK), and incubated at 15°C, 25°C, and 35°C for 60 days. Soil respiration, C fractions and bacterial and fungal community structure were measured SM had greater soil organic carbon and potential C mineralization and a similar microbial biomass carbon throughout the incubation when compared with CK. Soil respiration increased with increasing temperature and its temperature sensitivity (Q10) was lower with SM than CK. Similar microbial community composition was found in the soils with SM and CK before incubation. However, SM had a greater bacterial richness and the relative abundances of Proteobacteria, Acidobacteria, Nitrospirae, Planctomycetes, Bacteroidetes, and Basidiomycota, but lower relative abundances of Actinobacteria, Chloroflexi, and Ascomycota than CK after incubation. Bacterial richness and diversity were greater at 15°C and 25°C than 35°C, but there was no difference in fungal richness and diversity among the incubation temperatures. As temperature increased, the relative abundances of Chloroflexi, Acidobacteria, and Bacteroidetes decreased, but Gemmatimonadetes and Ascomycota increased, and were significantly correlated with soil C fractions and respiration. These findings indicated that the effect of straw mulching on soil C cycling and microbial community structure can be highly modified by increasing temperature.


Assuntos
Produção Agrícola/métodos , Microbiologia do Solo , Solo/química , Bactérias/classificação , Bactérias/isolamento & purificação , Carbono/análise , Fungos/classificação , Fungos/isolamento & purificação , Microbiota , Micobioma , Temperatura , Zea mays/crescimento & desenvolvimento
4.
PLoS One ; 15(8): e0237234, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32810176

RESUMO

China implemented the Action Plan for the Zero Increase of Fertilizer Use in 2015, which led to a decrease in fertilizer use. However, Will fertilizer use continue to reduce? With data obtained from 2006 to 2017, the paper used the logarithmic mean Divisia index (LMDI) method to analyze the scale effect, intensity effect and structural effect of fertilizer use change in China from three aspects: crops, regions and fertilizer types. Our finding suggests that (1) The intensity effect was the most critical factor affecting the decline in fertilizer use in China. (2) The sowing scale and fertilization intensity of grain, vegetables and fruits had the most significant driving effect on fertilizer reduction. (3) The three effects of each region were different in space, and the eastern region contributed most to the fertilizer decrement. (4) Nitrogen fertilizer and compound fertilizer had the most considerable influence on fertilizer reduction, especially in the sowing scale and fertilization intensity since 2009. The government should establish a fertilizer reduction management system, which includes scale control, intensity reduction, structural adjustment and other measures.


Assuntos
Produção Agrícola , Produtos Agrícolas/crescimento & desenvolvimento , Fertilizantes/provisão & distribução , Algoritmos , China , Produção Agrícola/economia , Produção Agrícola/métodos , Desenvolvimento Econômico , Nitrogênio/provisão & distribução
5.
Ecotoxicol Environ Saf ; 205: 111162, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32836158

RESUMO

The mechanisms of intercropping increasing plant biomass, cadmium accumulation, and organic acids secreted in rhizosphere soil are still unclear. Oilseed rape and intercrops were grown in boxes separated either with no barrier between the compartments or by a nylon mesh barrier (37 µm) to license partial root interaction, or a solid barrier to stop any root interactions. Two intercropping systems (oilseed rape-faba bean and oilseed rape-ryegrass) were carried out in soil with Cd content of 5 mg/kg. The intermingling of roots between oilseed rape and faba bean enhanced the biomass of oilseed rape. However, the biomass was negatively affected implying the higher nutrient apportionment to the ryegrass than oilseed rape. Oilseed rape intercropping with both faba bean and ryegrass played a positive role in the shoot Cd concentration of oilseed rape. The intermingling of roots played a positive role in the citric and malic acids when intercropping with faba bean. A remarkable increase in water-soluble Cd and DTPA-Cd content was observed during oilseed rape-faba bean complete root interaction treatment, up to 175.00% and 46.65%, respectively, which compare with the monoculture treatment. In both systems, the translocation factor values were higher for oilseed rape (O-F system) than for the other test plants and were always >1. Thus the Cd removal potential of oilseed rape can be further improved in the future by optimizing agronomic practices and intercropping with faba bean.


Assuntos
Brassica napus/crescimento & desenvolvimento , Cádmio/metabolismo , Produção Agrícola/métodos , Lolium/crescimento & desenvolvimento , Poluentes do Solo/metabolismo , Vicia faba/crescimento & desenvolvimento , Bioacumulação , Biomassa , Brassica napus/metabolismo , China , Lolium/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Rizosfera , Solo/química , Vicia faba/metabolismo
6.
PLoS One ; 15(7): e0235872, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32673343

RESUMO

Fertilizer discharge process is a critical part of fertilizer application, as it affects the fertilizer discharge rate and uniformity of fertilizer application. In this study, a spiral grooved-wheel fertilizer discharge device was designed to replace the conventional straight grooved-wheel. Comparisons of the fertilizer discharge performance of the two grooved-wheel types were performed through tests and simulations using the discrete element method (DEM). The discharge performance of the two discharge devices was assessed by measuring the discharge mass rate, discharge uniformity, and the falling velocity of the fertilizer particles. Results showed that under similar conditions, the fertilizer discharge mass rate of the spiral grooved-wheel was higher than that of the straight grooved-wheel. The fertilizer discharge uniformity of the spiral grooved-wheel was much better than that of the straight grooved-wheel. The average falling velocity of fertilizer particles through the discharge spout was higher under the spiral grooved-wheel. The relative errors between the test and simulation results for the discharge mass rates, discharge uniformity, and particle falling velocities of the spiral grooved-wheel were all less than 10%. The developed spiral grooved-wheel exhibited a better performance than the conventional straight grooved-wheel, in all the aspects examined. The results serve as a theoretical basis for guiding the design of high-performance fertilizer applicators.


Assuntos
Produção Agrícola/instrumentação , Fertilizantes , Simulação por Computador , Produção Agrícola/métodos
7.
PLoS One ; 15(7): e0235868, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32716963

RESUMO

Cover crop mixtures can provide multiple ecosystem services but provisioning of these services is contingent upon the expression of component species in the mixture. From the same seed mixture, cover crop mixture expression varied greatly across farms and we hypothesized that this variation was correlated with soil inorganic nitrogen (N) concentrations and growing degree days. We measured fall and spring biomass of a standard five-species mixture of canola (Brassica napus L.), Austrian winter pea (Pisum sativum L), triticale (x Triticosecale Wittm.), red clover (Trifolium pratense L.) and crimson clover (Trifolium incarnatum L.) seeded at a research station and on 8 farms across Pennsylvania and New York in two consecutive years. At the research station, soil inorganic N (soil iN) availablity and cumulative fall growing degree days (GDD) were experimentally manipulated through fertilizer additions and planting date. Farmers seeded the standard mixture and a "farm-tuned" mixture of the same five species with component seeding rates adjusted to achieve farmer-desired services. We used Structural Equation Modeling to parse out the effects of soil iN and GDD on cover crop mixture expression. When soil iN and fall GDD were high, canola dominated the mixture, especially in the fall. Low soil iN favored legume species while a shorter growing season favored triticale. Changes in seeding rates influenced mixture composition in fall and spring but interacted with GDD to determine the final expression of the mixture. Our results show that when soil iN availability is high at the time of cover crop planting, highly competitive species can dominate mixtures which could potentially decrease services provided by other species, especially legumes. Early planting dates can exacerbate the dominance of aggressive species. Managers should choose cover crop species and seeding rates according to their soil iN and GDD to ensure the provision of desired services.


Assuntos
Produção Agrícola/métodos , Modelos Estatísticos , Nitrogênio/análise , Estações do Ano , Solo/química , Brassica/crescimento & desenvolvimento , Medicago/crescimento & desenvolvimento , Ervilhas/crescimento & desenvolvimento , Triticale/crescimento & desenvolvimento
8.
PLoS One ; 15(7): e0235620, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32645043

RESUMO

Accurate information about the spatiotemporal variability of actual crop evapotranspiration (ETa), crop coefficient (Kc) and water productivity (WP) is crucial for water efficient management in the agriculture. The Earth Engine Evapotranspiration Flux (EEFlux) application has become a popular approach for providing spatiotemporal information on ETa and Kc worldwide. The aim of this study was to quantify the variability of water consumption (ETa) and the Kc for an irrigated commercial planting of soybeans based on the EEFlux application in the western region of the state of Bahia, Brazil. The water productivity (WP) for the fields was also obtained. Six cloud-free images from Landsat 7 and 8 satellites, acquired during the 2016/17 soybean growing season were used and processed on the EEFlux platform. The ETa from EEFlux was compared to that of the modified FAO (MFAO) approach using the following statistical metrics: Willmot's index of agreement (d-index), root mean square error (RMSE), mean absolute error (MAE) and mean bias error (MBE). The Kc from EEFlux was compared to the Kc used in the soybean field (Kc FAO-based) and to the Kc values obtained in different scientific studies using the d-index. A similar procedure was performed for WP. Our results reveal that EEFlux is able to provide accurate information about the variability of ETa and the Kc of soybean fields. The comparison between ETa EEFlux and ETa MFAO showed good agreement based on the d-index, with values of 0.85, 0.83 and 0.89 for central pivots 1, 2 and 3, respectively. However, EEFlux tends to slightly underestimate ETa. The Kc EEFlux showed good accordance with the Kc values considered in this study, except in phase II, where a larger difference was observed; the average WP of the three fields (1.14 kg m-3) was higher than that in the majority of the previous studies, which is a strong indicator of the efficient use of water in the studied soybean fields. The study showed that EEFlux, an innovative and free tool for access spatiotemporal variability of ETa and Kc at global scale is very efficient to estimate the ETa and Kc on different growth stages of soybean crop.


Assuntos
Irrigação Agrícola/métodos , Produção Agrícola/métodos , Produtos Agrícolas/fisiologia , Software , Soja/fisiologia , Clima , Produtos Agrícolas/crescimento & desenvolvimento , Modelos Estatísticos , Transpiração Vegetal , Soja/crescimento & desenvolvimento , Análise Espaço-Temporal
9.
Proc Natl Acad Sci U S A ; 117(31): 18385-18392, 2020 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-32690686

RESUMO

Transgenic crops that produce insecticidal proteins from Bacillus thuringiensis (Bt) can suppress pests and reduce insecticide sprays, but their efficacy is reduced when pests evolve resistance. Although farmers plant refuges of non-Bt host plants to delay pest resistance, this tactic has not been sufficient against the western corn rootworm, Diabrotica virgifera virgifera In the United States, some populations of this devastating pest have rapidly evolved practical resistance to Cry3 toxins and Cry34/35Ab, the only Bt toxins in commercially available corn that kill rootworms. Here, we analyzed data from 2011 to 2016 on Bt corn fields producing Cry3Bb alone that were severely damaged by this pest in 25 crop-reporting districts of Illinois, Iowa, and Minnesota. The annual mean frequency of these problem fields was 29 fields (range 7 to 70) per million acres of Cry3Bb corn in 2011 to 2013, with a cost of $163 to $227 per damaged acre. The frequency of problem fields declined by 92% in 2014 to 2016 relative to 2011 to 2013 and was negatively associated with rotation of corn with soybean. The effectiveness of corn rotation for mitigating Bt resistance problems did not differ significantly between crop-reporting districts with versus without prevalent rotation-resistant rootworm populations. In some analyses, the frequency of problem fields was positively associated with planting of Cry3 corn and negatively associated with planting of Bt corn producing both a Cry3 toxin and Cry34/35Ab. The results highlight the central role of crop rotation for mitigating impacts of D. v. virgifera resistance to Bt corn.


Assuntos
Besouros/fisiologia , Produção Agrícola/métodos , Endotoxinas/farmacologia , Doenças das Plantas/parasitologia , Plantas Geneticamente Modificadas/imunologia , Zea mays/imunologia , Animais , Bacillus thuringiensis/genética , Bacillus thuringiensis/metabolismo , Besouros/efeitos dos fármacos , Produção Agrícola/economia , Endotoxinas/genética , Endotoxinas/metabolismo , Resistência a Inseticidas , Iowa , Controle Biológico de Vetores/economia , Doenças das Plantas/economia , Doenças das Plantas/imunologia , Doenças das Plantas/prevenção & controle , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/parasitologia , Soja/crescimento & desenvolvimento , Zea mays/genética , Zea mays/crescimento & desenvolvimento , Zea mays/parasitologia
10.
Proc Natl Acad Sci U S A ; 117(32): 19131-19135, 2020 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-32719119

RESUMO

Scaling current cereal production to a growing global population will be a challenge. Wheat supplies approximately one-fifth of the calories and protein for human diets. Vertical farming is a possible promising option for increasing future wheat production. Here we show that wheat grown on a single hectare of land in a 10-layer indoor vertical facility could produce from 700 ± 40 t/ha (measured) to a maximum of 1,940 ± 230 t/ha (estimated) of grain annually under optimized temperature, intensive artificial light, high CO2 levels, and a maximum attainable harvest index. Such yields would be 220 to 600 times the current world average annual wheat yield of 3.2 t/ha. Independent of climate, season, and region, indoor wheat farming could be environmentally superior, as less land area is needed along with reuse of most water, minimal use of pesticides and herbicides, and no nutrient losses. Although it is unlikely that indoor wheat farming will be economically competitive with current market prices in the near future, it could play an essential role in hedging against future climate or other unexpected disruptions to the food system. Nevertheless, maximum production potential remains to be confirmed experimentally, and further technological innovations are needed to reduce capital and energy costs in such facilities.


Assuntos
Produção Agrícola/métodos , Triticum/crescimento & desenvolvimento , Clima , Produção Agrícola/economia , Produção Agrícola/instrumentação , Ambiente Controlado , Estações do Ano , Temperatura
12.
Ecotoxicol Environ Saf ; 201: 110812, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32512419

RESUMO

Pesticides are widely used chemical compounds in agriculture to destroy insects, pests and weeds. In modern era, they form an indispensable part of agricultural and health practices. Globally, nearly 3 billion kg of pesticides are used every year with a budget of ~40 billion USD. This extensive usage has increased the crop yield as well as led to significant reduction in harvest losses and thereby, enhanced food availability. On the other hand, indiscriminate usage of these chemicals has led to several environmental implications and caused adverse effects on human health. Epidemiological evidences have revealed the harmful effects of pesticides exposure on various organs including liver, brain, lungs and colon. Recent investigations have shown that pesticides can also lead to fatal consequences such as cancer among individuals. These chemicals enter ecosystem, thus hampering the sensitive environmental equilibrium through bio-accumulation. Due to their non-biodegradable nature, they can persist in nature for years and are regarded as potent biohazard. Worldwide, very few surveillance methods have been considered, which can bring awareness among the individuals, therefore the present review is an attempt to delineate consequences induced by various types of pesticide exposure on the environment. Further, the prospective of biopesticides use could facilitate the increase of crop production without compromising human health.


Assuntos
Agentes de Controle Biológico/toxicidade , Exposição Ambiental/efeitos adversos , Poluentes Ambientais/toxicidade , Praguicidas/toxicidade , Agentes de Controle Biológico/química , Produção Agrícola/métodos , Ecossistema , Exposição Ambiental/análise , Poluentes Ambientais/química , Humanos , Praguicidas/química
13.
PLoS One ; 15(6): e0233783, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32497087

RESUMO

Managing pests in carrot production is challenging. Endophytic microbes have been demonstrated to improve the health and productivity of many crops, but factors affecting endophyte dynamics in carrot is still not well understood. The goal of this study was to determine how crop management system and carrot genotype interact to affect the composition and potential of endophytes to mitigate disease caused by Alternaria dauci, an important carrot pathogen. Twenty-eight unique isolates were collected from the taproots of nine diverse genotypes of carrot grown in a long-term trial comparing organic and conventional management. Antagonistic activity was quantified using an in vitro assay, and potential for individual isolates to mitigate disease was evaluated in greenhouse trials using two carrot cultivars. Results confirm that carrot taproots are colonized by an abundant and diverse assortment of bacteria and fungi representing at least distinct 13 genera. Soils in the organic system had greater total organic matter, microbial biomass and activity than the conventional system and endophyte composition in taproots grown in this system were more abundant and diverse, and had greater antagonistic activity. Carrot genotype also affected endophyte abundance as well as potential for individual isolates to affect seed germination, seedling growth and tolerance to A. dauci. The benefits of endophytes on carrot growth were greatest when plants were subject to A. dauci stress, highlighting the importance of environmental conditions in the functional role of endophytes. Results of this study provide evidence that endophytes can play an important role in improving carrot performance and mediating resistance to A. dauci, and it may someday be possible to select for these beneficial plant-microbial relationships in carrot breeding programs. Implementing soil-building practices commonly used in organic farming systems has potential to promote these beneficial relationships and improve the health and productivity of carrot crops.


Assuntos
Alternaria/fisiologia , Produção Agrícola/métodos , Daucus carota/genética , Daucus carota/microbiologia , Endófitos/fisiologia , Genótipo , Doenças das Plantas/microbiologia , Proteção de Cultivos/métodos , Daucus carota/crescimento & desenvolvimento , Endófitos/isolamento & purificação , Germinação , Solo/química , Microbiologia do Solo
14.
PLoS One ; 15(6): e0233735, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32497128

RESUMO

Many fertilization models have been created to scientifically determine the amount of fertilization. With the same purpose, we constructed a nitrogen (N) application model, the leaf value model, which can make N fertilizer decisions in a timely, fast and nondestructive manner during rice planting. However, only one area (A1, Jiuzhou Town, Xixiu District, Guizhou Province) and one cultivar (Qyou6) were involved in the construction of the leaf value model. Its stability and applicability could not be well evaluated. Thus, we chose another area (A2, Jiuzhou Town, Huangping County, Guizhou Province) in Guizhou Province and carried out the experiment by using four cultivars (Nie5you5399, Qyou6, Yixiangyou2115 and Zhongzheyou8) for the leaf value model construction. Compared with the average value of apparent total N uptake (Nz) obtained in 2 years in the A1 area, that in the Qyou6 leaf value model in the A2 area increased by 12%, reaching 635.72 kg ha-1, whereas the corresponding target yield changed slightly, reaching 10,999.90 kg ha-1. Simultaneously, the linear relationship between several good SPAD value-derived indexes (Ys) and apparent N supply of the field (Nx) was still significant or extremely significant in the Qyou6 leaf value model. Compared with the A1 area, it slightly differed, and the R2 of SPADL1 was higher than that of SPADL3×L4/mean. In the leaf value model of the other three cultivars, the relationship between yield and Nx and that between Ys and Nx were significant or extremely significant. The Nz of Yixiangyou2115 and Zhongzheyou8 (618.33 and 617.76 kg ha-1) were close to that of Qyou6 and the corresponding target yields were 10313.36 and 10301.99 kg ha-1, respectively. The Nz and target yield of Nie5you5399 were lowest at 546.63 and 10680.24 kg ha-1, respectively. In general, this study showed that relationships used in the construction of leaf value model had certain stability and applicability to difference areas and cultivars. The leaf value model can be considered in N fertilizer decision-making of rice planting management.


Assuntos
Fertilizantes , Modelos Biológicos , Nitrogênio/administração & dosagem , Oryza/fisiologia , Folhas de Planta/fisiologia , Clorofila/análise , Produção Agrícola/métodos , Oryza/anatomia & histologia , Oryza/química , Folhas de Planta/química , Solo/química
15.
PLoS One ; 15(6): e0233723, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32484821

RESUMO

Farmland management and irrigation scheduling are vital to a productive agricultural economy. A multistage stochastic programming model is proposed to maximize farmers' annual profit under uncertainty. The uncertainties considered include crop prices, irrigation water availability, and precipitation. During the first stage, pre-season decisions including seed type and plant density are made, while determinations of when to irrigate and how much water to be used for each irrigation are made in the later stages. The presented case study, based on a farm in Nebraska, U.S.A., showed that a 10% profit increase could be achieved by taking the corn price and irrigation water availability uncertainties into consideration using two-stage stochastic programming. An additional 13% profit increase could be achieved by taking precipitation uncertainty into consideration using multistage stochastic programming. The stochastic model outperforms the deterministic model, especially when there are limited water supplies. These results indicate that multistage stochastic programming is a promising method for farm-scale irrigation management and can increase farm profitability.


Assuntos
Irrigação Agrícola/métodos , Modelos Teóricos , Irrigação Agrícola/estatística & dados numéricos , Clima , Produção Agrícola/métodos , Produção Agrícola/estatística & dados numéricos , Nebraska , Processos Estocásticos , Incerteza , Zea mays/crescimento & desenvolvimento
16.
PLoS One ; 15(5): e0233674, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32469984

RESUMO

Timing and rate of nitrogen (N) fertilizer application can influence maize (Zea mays L.) grain yield, N uptake, and nitrogen use efficiency (NUE) parameters, but results have been inconsistent across the upper Midwest. This study compared single (fall and preplant) and split applications of differing N rates for maize under irrigated conditions on loamy sand at Becker, MN and under rainfed conditions on loam and clay loam soils at Lamberton, MN and Waseca, MN, respectively, in 2014 to 2016. Fall and preplant applications of N were applied at recommended and 125% of recommended rates (RN) according to University of Minnesota guidelines. Split-application treatments included a two-way (Sp, applied at 75% and 100% of RN) and a three-way split (TSp applied at 50%, 75%, and 100% of RN), with the total N rate equally split among application times. At Becker, maize grain yield with TSp was 12.6 to 15.7 Mg ha-1 among years and significantly greater than that with fall or preplant treatments. The TSp treatment also improved agronomic efficiency (AE) and recovery efficiency (RE) by an average of 30% over fall or preplant treatments. At Lamberton, maize grain yield, AE and RE did not differ among treatments. However, TSp75 improved AE by 8.3 kg kg-1 while producing comparable yields to fall and preplant treatments. At Waseca, Sp or TSp improved grain yield and AE compared with fall treatments. These results suggest that split applications of N can increase maize grain yield, AE, and RE on irrigated coarse-textured soils and applying N fertilizer near planting or as a split application can improve N management on non-irrigated clay loam soils.


Assuntos
Produção Agrícola/métodos , Fertilizantes , Nitrogênio , Zea mays/crescimento & desenvolvimento , Irrigação Agrícola , Fertilizantes/análise , Nitrogênio/análise , Nitrogênio/metabolismo , Chuva , Solo/química , Zea mays/metabolismo
17.
PLoS One ; 15(5): e0233303, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32437419

RESUMO

This study compares thirteen rice-based cropping systems in the coastal part of West Bengal, India in terms of productivity, profitability, energetics, and emissions. Information on the crop management practices of these systems was collected on 60 farms through a questionnaire survey. Rice-bitter gourd system was observed to have the highest system yield (49.88 ± 4.34 tha-1yr-1) followed by rice-potato-ridge gourd (37.78 ± 2.77 tha-1yr-1) and rice-potato-pumpkin (36.84 ± 2.04 tha-1yr-1) systems. The rice-bitter gourd system also recorded the highest benefit:cost ratio (3.92 ± 0.061). The lowest system yield and economics were recorded in the rice-fallow-fallow system. Rice-sunflower system recorded highest specific energy (2.54 ± 0.102 MJkg-1), followed by rice-rice (2.14 ± 0.174 MJkg-1) and rice-fallow-fallow (1.91 ± 0.327 MJkg-1) systems, lowest being observed in the rice-bitter gourd (0.52 ± 0.290 MJkg-1) and rice-pointed gourd (0.52 ± 0.373 MJkg-1) systems. Yield-scaled GHGs (YSGHG) emission was highest (1.265 ± 0.29 t CO2eqt-1 system yield) for rice-fallow-fallow system and was lowest for rice-vegetable systems. To estimate the uncertainty of the YSGHG across different systems under study, Monte-Carlo Simulation was performed. It was observed that there was a 5% probability of recording YSGHG emission > 1.15 t CO2eqt-1 system yield from different cropping systems in the present experiment. Multiple system properties such as productivity, economics, energy, and emission from all rice-based systems taken together, the rice-vegetable system performed consistently well across parameters and may be practised for higher economic returns with judicious and sustainable utilization of resources in the coastal saline tracts of the region.


Assuntos
Produtos Agrícolas/economia , Gases de Efeito Estufa/metabolismo , Oryza/metabolismo , Dióxido de Carbono/metabolismo , Mudança Climática/economia , Simulação por Computador , Produção Agrícola/economia , Produção Agrícola/métodos , Produtos Agrícolas/crescimento & desenvolvimento , Produtos Agrícolas/metabolismo , Índia , Metano/metabolismo , Método de Monte Carlo , Óxido Nitroso/metabolismo , Oryza/crescimento & desenvolvimento , Medição de Risco , Salinidade
18.
Environ Monit Assess ; 192(5): 323, 2020 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-32361893

RESUMO

A 2-year field experiment was carried out on rice (Oryza sativa, Japonica type) cultivation in South Korea. The objective of this study was to investigate the effect of application of liquid pig manure on biomass production and nutrient supply of green barley (Hordeum vulgare L.) and hairy vetch (Vicia villosa Roth) green manure crops and to evaluate the effect of nutrients supplied from these sources on rice yield and soil quality in a rice-green manure crop rotation system. Over the 2-year study period, application of liquid pig manure increased biomass production of green manure crops of barley and hairy vetch by more than 216% and 135%, respectively, compared with without liquid pig manure. Moreover, the results showed that the application of liquid pig manure significantly increased the nutrient supply levels in green barley- and hairy vetch-treated areas. Positive effects related to nutrient supply in green barley and hairy vetch treated with liquid pig manure were observed on rice yield, soil chemical characteristics, and microbial biomass C and N contents. In conclusion, the addition of liquid pig manure systems using green manure crops of green barley and hairy vetch improved rice productivity and soil quality. It is suggested that these combinations can be effective in developing resource cycling agriculture in a rice-green manure crop rotation system as it reduces the need for inorganic fertilizer.


Assuntos
Produção Agrícola , Fertilizantes , Esterco , Oryza , Animais , Produção Agrícola/métodos , Monitoramento Ambiental , Nitrogênio/metabolismo , República da Coreia , Solo/química , Suínos
19.
PLoS One ; 15(5): e0233642, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32437444

RESUMO

Microbial community functional diversity is a sensitive indicator of soil quality, soil management such as tillage and crop residue which can affect the microbial community functional diversity of paddy field. However, there is still limited information about the influence of different tillage and crop residue management on rhizosphere soil microbial community functional diversity in a double-cropping rice (Oryza sativa L.) field. Therefore, four tillage treatments were set up in paddy field, tillage treatments were included: conventional tillage with residue incorporation (CT), rotary tillage with residue incorporation (RT), no-tillage with residue retention (NT), and rotary tillage with residue removed as control (RTO). And the effects of CT, RT, NT, and RTO treatments on the average well color development (AWCD), genetic diversity indices and carbon source utilization of rhizosphere soil were studied in the present paper. The results showed that the values of AWCD with CT, RT and NT treatments were higher than that of RTO treatment. It was implied that application of crop residue management resulted in the variation of the carbon utilization efficiency of rhizosphere soil microbial communities. At maturity stages of early and late rice, the Richness indices, Shannon indices and McIntosh indices with CT treatment were significantly higher than that of RTO treatment, and with the order as CT>RT>NT>RTO. Principal component analysis (PCA) results indicated that there were significant differences in carbon substrate utilization patterns among different tillage treatments. Carbohydrates and amino acids were the main carbon resources utilized by rhizosphere soil microbes. Therefore, the combined application of tillage with crop residue management could significantly increase the rhizosphere soil microbial community functional diversity in the double-cropping paddy field of southern China.


Assuntos
Produção Agrícola/métodos , Oryza/crescimento & desenvolvimento , Rizosfera , Microbiologia do Solo , China
20.
PLoS One ; 15(5): e0232554, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32374758

RESUMO

Recycled paper has the potential to be used as a mulch for vegetable production and can be adopted for the cultivation of Italian zucchini. However, there have been no studies about the water savings or crop coefficient values used in irrigation management in this system; therefore, there is a need for more research. In view of the above, this study aimed to evaluate the effects of recycled paper mulch on evaporation and evapotranspiration in Italian zucchini and to determine the crop coefficients in its developmental stages. The study was carried out in two cultivation cycles conducted at the Lysimetric Station in Viçosa, MG, Brazil. The experiments were installed in a randomized block design with four replicates. Four lysimeter cultivation treatments were applied: without mulch (C); with recycled paper as mulch (CP); with only recycled paper (P); and with Bahia grass (G). Irrigation and drainage measurements were performed daily to calculate the crop and reference evapotranspiration, and thus the crop coefficient (Kc) values. The following characteristics were evaluated: fruit yield, NDVI and water productivity. For the cultivation of Italian zucchini using paper as mulch, Kc values of 0.54, 0.77 and 0.44 and Kcb values of 0.15, 0.45 and 0.18 are recommended for the initial, intermediate and final stages, respectively. NDVI can be used to estimate the Kc values for Italian zucchini. The use of recycled paper as mulch reduces the water consumption of Italian zucchini.


Assuntos
Produção Agrícola/métodos , Cucurbita/crescimento & desenvolvimento , Verduras/crescimento & desenvolvimento , Irrigação Agrícola , Brasil , Cucurbita/metabolismo , Itália , Papel , Transpiração Vegetal , Reciclagem , Solo , Verduras/metabolismo , Água
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