Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 49.190
Filtrar
1.
Braz. j. biol ; 84: e249230, 2024. tab, graf
Artículo en Inglés | MEDLINE, LILACS, VETINDEX | ID: biblio-1345556

RESUMEN

Abstract The presence of weeds in areas of agricultural activities is a hinderance to the development of these activities. It is important to take advantage of the vast open spaces suitable for agriculture and provide food security for humans, and also it is an important indicator for determining the feasibility of growing crops, benefiting from yield and determining the percentage of loss, clearing fields through agricultural practices, that protect crops from weed attack and agricultural practice method must be followed that will reduce weed presence. This study was conducted during the years 2018 to 2020 to evaluate Portulacaceae of Flora in the Taif area in the Kingdom of Saudi Arabia at different altitudes (Area 1 =1700 m, Area 2 =1500 m, Area 3 =1500 m, Area 4 =500 m ِ Area 5 = 2200 m, and Area 6 = 2200 m). The results show that there were 2,816 individuals of Portulaca oleracea weed, with the highest density found in A 1, followed by A 2, while in A 5 and A 6, no weeds were recorded. The highest density of weeds were in the Pomegranate fields, followed by Grape fields. The lowest density was found in A man field. The results of this study will help to take the necessary measures to combat weeds and its management in areas of agricultural activity, while more studies are needed to survey the ecology of weeds of Taif in The Kingdom of Saudi Arabia.


Resumo A presença de plantas daninhas em áreas de atividades agrícolas é um entrave ao desenvolvimento dessas atividades. É importante aproveitar os vastos espaços abertos adequados para a agricultura e dar segurança alimentar para o homem. Também é um indicador importante para determinar a viabilidade de cultivo de lavouras, beneficiando-se da produtividade e determinando o percentual de perda, desmatando campos agrícolas, práticas que protegem as lavouras do ataque de ervas daninhas, e métodos de práticas agrícolas devem ser seguidos para reduzir a presença de ervas daninhas. Este estudo foi realizado durante os anos de 2018 a 2020 para avaliar Portulacaceae de flora na área de Taif, no Reino da Arábia Saudita, em diferentes altitudes (Área 1 = 1.700 m, Área 2 = 1.500 m, Área 3 = 1.500 m, Área 4 = 500 m, Área 5 = 2.200 m, e Área 6 = 2.200 m). Os resultados mostram que houve 2.816 indivíduos de planta daninha Portulaca oleracea, com a maior densidade encontrada em A 1, seguida de A 2, enquanto em A 5 e A 6, nas plantas daninhas foram registrados. A maior densidade de ervas daninhas estava nos campos de romã, seguido pelos campos de uva. A densidade mais baixa foi encontrada no campo A man. Os resultados deste estudo ajudarão a tomar as medidas necessárias para combater as ervas daninhas e seu manejo em áreas de atividade agrícola, enquanto mais estudos são necessários para levantar a ecologia das ervas daninhas de Taif na Arábia Saudita.


Asunto(s)
Humanos , Portulacaceae , Arabia Saudita , Productos Agrícolas , Agricultura , Malezas
2.
Braz. j. biol ; 83: e248420, 2023. tab, graf
Artículo en Inglés | MEDLINE, LILACS, VETINDEX | ID: biblio-1339367

RESUMEN

Abstract Very little is known about the malacofauna in district Swat of Khyber Pakhtunkhwa province, situated in the Northern part of Pakistan. The Swat valley possesses a variety of suitable environmental conditions, providing different types of habitats for both flora and fauna. Taken into consideration these points, the present study was conducted to explore the terrestrial snails diversity in agricultural and non-agricultural fields in the lower Swat valley. A total of 417 shells were collected from three sites: Kokarai, Kanju Township, and Deolai. Based on conchological features, three families: Bradybaenidae, Hygromiidae, and Zonitidae were identified using different terrestrial snail keys. In Kokarai and Deolai, shells of members of all the above-mentioned families were found from agricultural fields. In Kanju Township, shells of members of the family Bradybaenidae and Zonitidae were found. From these findings, it was concluded that district Swat possesses a significant malacofauna which was unexplored before and aided more to the existing literature on malacofauna. It also supports the idea that the agroecosystem is rich in species diversity. Further in-depth and extensive study is recommended to be carried out for a detailed taxonomy of the described terrestrial gastropod families.


Resumo Muito pouco se sabe sobre a malacofauna no distrito de Swat, na província de Khyber Pakhtunkhwa, situada na parte norte do Paquistão. O vale do Swat possui uma variedade de condições ambientais adequadas, proporcionando diferentes tipos de habitats para a flora e a fauna. Levando em consideração esses pontos, o presente estudo foi conduzido para explorar a diversidade dos caracóis terrestres em campos agrícolas e não agrícolas no vale inferior de Swat. Um total de 417 conchas foram coletadas em três locais: Kokarai, Kanju Township e Deolai. Com base em características concológicas, três famílias: Bradybaenidae, Hygromiidae e Zonitidae foram identificadas usando diferentes chaves de caramujos terrestres. Em Kokarai e Deolai, conchas de membros de todas as famílias mencionadas acima foram encontradas em campos agrícolas. No município de Kanju, foram encontradas conchas de membros da família Bradybaenidae e Zonitidae. A partir dessas constatações, concluiu-se que o distrito de Swat possui uma malacofauna significativa que antes era inexplorada e ajudava mais a literatura existente sobre a malacofauna. Também apoia a ideia de que o agroecossistema é rico em diversidade de espécies. Recomenda-se a realização de um estudo mais aprofundado e extenso para uma taxonomia detalhada das famílias de gastrópodes terrestres descritas.


Asunto(s)
Humanos , Animales , Ecosistema , Agricultura , Pakistán , Caracoles
3.
Braz. j. biol ; 83: e249847, 2023. tab, graf
Artículo en Inglés | MEDLINE, LILACS, VETINDEX | ID: biblio-1339414

RESUMEN

Abstract The Indian crested porcupine (Hystrix indica) is a vertebrate pest of agricultural lands and forest. The study was aimed to report the damage to local crops by the Indian crested porcupine (Hystrix indica) in the Muzaffarabad District. A survey was conducted to identify the porcupine-affected areas and assess the crop damage to the local farmers in district Muzaffarabad Azad Jammu and Kashmir (AJK) from May 2017 to October 2017. Around 19 villages were surveyed, and a sum of 191 semi-structured questionnaires was distributed among farmers. Crop damage was found highest in village Dhanni where a porcupine destroyed 175 Kg/Kanal of the crops. Regarding the total magnitude of crop loss, village Danna and Koomi kot were the most affected areas. More than half (51.8%) of the respondents in the study area suffered the economic loss within the range of 101-200$, and (29.8%) of the people suffered losses in the range of 201-300$ annually. Among all crops, maize (Zea mays) was found to be the most damaged crop ranging between 1-300 Kg annually. In the study area, porcupine also inflicted a lot of damages to some important vegetables, including spinach (Spinacia oleracea), potato (Solanum tuberosum) and onion (Allium cepa). It was estimated that, on average, 511Kg of vegetables are destroyed by porcupine every year in the agricultural land of Muzaffarabad. It was concluded that the Indian crested porcupine has a devastating effect on agriculture which is an important source of income and food for the local community. Developing an effective pest control strategy with the help of the local government and the Wildlife department could help the farmers to overcome this problem.


Resumo O porco-espinho de crista indiano (Hystrix indica) é uma praga vertebrada de terras agrícolas e florestais. No estudo atual, o dano às plantações locais pelo porco-espinho de crista indiano (Hystrix indica) foi relatado pela primeira vez no distrito de Muzaffarabad. O estudo foi projetado para investigar a perda econômica causada pelo porco-espinho de crista indiano (Hystrix indica) nos distritos de Muzaffarabad, Azad Jammu e Caxemira (AJK) de maio de 2017 a outubro de 2017. Um estudo baseado em pesquisa foi conduzido para identificar as áreas afetadas por porcos-espinhos e avaliar os danos às colheitas para os agricultores locais. Cerca de 19 aldeias foram pesquisadas e um total de 191 questionários semiestruturados foi distribuído entre os agricultores. Os danos às colheitas foram encontrados mais intensamente na aldeia Dhanni, onde um porco-espinho destruiu 175 kg / Kanal das colheitas. Em relação à magnitude total da perda de safra, as aldeias Danna e Koomi Kot foram as áreas mais afetadas. Mais da metade (51,8%) dos entrevistados na área de estudo sofreu perdas econômicas na faixa de 101-200 $, e 29,8% das pessoas sofreram perdas na faixa de 201-300 $ anualmente. Entre todas as culturas, o milho (Zea mays) foi considerado a cultura mais danificada, variando entre 1-300 kg anualmente. Na área de estudo, o porco-espinho também causou muitos danos a alguns vegetais importantes, incluindo espinafre (Spinacia oleracea), batata (Solanum tuberosum) e cebola (Allium cepa). Estimou-se que, em média, 511 kg de vegetais são destruídos pelo porco-espinho todos os anos nas terras agrícolas de Muzaffarabad. Concluiu-se que o porco-espinho de crista indiano tem um efeito devastador na agricultura, que é importante fonte de renda e alimento para a comunidade local. O desenvolvimento de uma estratégia eficaz de controle de pragas com a ajuda do governo local e do Departamento de Vida Selvagem pode ajudar os agricultores a superar esse problema.


Asunto(s)
Humanos , Animales , Puercoespines , Pakistán , Productos Agrícolas , Agricultura , Animales Salvajes
4.
Ying Yong Sheng Tai Xue Bao ; 33(3): 664-670, 2022 Mar.
Artículo en Chino | MEDLINE | ID: mdl-35524517

RESUMEN

Understanding the effects of different amounts of straw returning and nitrogen fertilizer application on soil CO2 emission from maize field can provide theoretical support for carbon sequestration and CO2 emission reduction and the implementation of black soil region conservation plan. Three rates of straw returning were set up in the semi-arid area of northwest Liaoning Province, China, i.e. 3000 (S1), 6000 (S2) and 9000 kg·hm-2(S3, full amount of straw returned to the field); crossed with three nitrogen fertilizer application rates in the sub-region, respectively, i.e. 105 (N1), 210 (N2, conventional nitrogen application rate) and 420 kg N·hm-2(N3). In addition, there was a control treatment (CK) without nitrogen fertilizer and straw returning. Soil samples were collected after 4 years field experiment with maize plantation. The influence of different treatments on maize field soil CO2 emission and the relationship between CO2 emission and soil dissolved organic carbon (DOC) and microbial biomass carbon (MBC) were investigated in an incubation experiment. The results showed that both of straw returning and nitrogen fertilizer application promoted soil CO2 emission in maize field, which were increased significantly with the increases of straw returning amount and nitrogen application amount. Nitrogen fertilizer application was the most important factor promoting soil CO2 emission in maize field. Straw returning combined with nitrogen fertilizer promoted soil CO2 emission by increasing microbial biomass and increasing DOC consumption. MBC and DOC stimulated soil CO2 emission significantly in maize field, and were mainly affected by their contents in the early stage of incubation. From the perspective of ensuring the fertilization of straw return to the field while reducing CO2 emissions, results from our experiment showed that 210 kg N·hm-2 conventional nitrogen application in combination with 6000 kg N·hm-2 straw returning (N2S2) was the most promising mode in the semi-arid area of northwest Liaoning Province.


Asunto(s)
Fertilizantes , Suelo , Agricultura/métodos , Carbono/análisis , Dióxido de Carbono , China , Nitrógeno/análisis , Zea mays
5.
Ying Yong Sheng Tai Xue Bao ; 33(3): 671-676, 2022 Mar.
Artículo en Chino | MEDLINE | ID: mdl-35524518

RESUMEN

Clarifying the differences of maize yield and its stability under long-term no-tillage with different stover mulching amounts can provide theoretical and technical supports for establishing and evaluating long-term conservation tillage pattern and promoting grain production. Based on a long-term conservation tillage field experiment in the mollisol area of Northeast China since 2007, we analyzed the interannual variation, variation coefficient and stability of maize yield during 2013 and 2019 across five treatments, i.e., no-tillage stover-free mulching (NT0), no-tillage with 33% stover mulching (NT33), no-tillage with 67% stover mulching (NT67) and no-tillage with 100% stover mulching (NT100), with the traditional ridge cropping (RT) as the control. The results showed that compared with RT, long-term no-tillage with stover mulching treatments could increase maize yield. NT100 had the highest increasing rate of 11.4%, followed by NT67 and NT0, with the increasing rate of 11.0% and 10.4%, respectively. Maize yield exhibited a nonlinear relationship with the amount of stover mulch. The variation coefficient of maize yield under multi-year no-tillage with different stover mulching could be sorted as NT67NT0>NT100>RT>NT33, indicating that NT67 treatment could significantly reduce the interannual fluctuation of maize yield and had better sustainability of yield. No-tillage stover mulching significantly increased soil total carbon and total nitrogen contents, which were significantly positively correlated with maize yield. In conclusion, compared with traditional tillage, no-tillage stover mulching could increase maize yield and soil carbon and nitrogen contents. Appropriate stover mulching (NT67)had the potential to improve the stability and sustainability of maize yield.


Asunto(s)
Agricultura , Zea mays , Agricultura/métodos , Carbono , China , Nitrógeno/análisis , Suelo
6.
Ying Yong Sheng Tai Xue Bao ; 33(3): 677-684, 2022 Mar.
Artículo en Chino | MEDLINE | ID: mdl-35524519

RESUMEN

A reduction of chemical fertilizers and improving fertilizer utilization rate are important for ensuring a balance between plant growth and minimizing the degradation of the black soil. We conducted a 2-year pot experiment with four treatments during 2019 and 2020, including T0: no fertilizer, T1: conventional use of chemical fertilizer, T2: 15% reduction of the chemical fertilizer combined with 400 kg·hm-2 of humic acid bio-fertilizer (HABF), and T3: 30% reduction of the chemical fertilizer combined with 600 kg·hm-2 of HABF, to examine the effect of reduction rates of chemical fertilizers combined with the HABF on soil microbial abundance, enzyme activity and nutrient content in maize cultivation. The results showed that the application of HABF significantly increased the abundance of soil bacteria and fungi, with the number of microbial colonies being positively correlated with the amount of HABF. When measured at the tassel stage of maize growth, T2 and T3 treatments significantly increased the activities of urease, sucrase, and catalase in soil by 11.4%-21.6%, 34.9%-46.7%, and 6.5%-13.4%, respectively. The available nitrogen contents in T2 and T3 treatments were higher than that in the T1 treatment by 8.2%-18.1%, which ensured the sufficient nitrogen supply to maize after the tassel stage. Soil available phosphorus and available potassium contents increased by 17.1%-121.0% and 9.6%-57.3%, respectively, compared with T1 treatment. With the increases of the amount of HABF, the activation effects of soil phosphorus and potassium and dry matter mass per plant increased significantly in T2 and T3 treatments compared with T1 treatment. In conclusion, HABF promoted the proliferation of soil bacteria and fungi, improved activities of catalase, urease, and sucrase, soil nutrient contents, and dry matter mass per plant. The 15% reduction of chemical fertilizer combined with 400 kg·hm-2 of HABF is the most suitable nutrient management strategy for maize production in black soil.


Asunto(s)
Fertilizantes , Suelo , Agricultura/métodos , Bacterias , Catalasa , Fertilizantes/análisis , Sustancias Húmicas , Nitrógeno/análisis , Fósforo , Potasio , Suelo/química , Sacarasa , Ureasa , Zea mays
7.
Ying Yong Sheng Tai Xue Bao ; 33(3): 694-702, 2022 Mar.
Artículo en Chino | MEDLINE | ID: mdl-35524521

RESUMEN

Different cropping patterns have their own economic and ecological significance. Developing cropping patterns suitable for local conditions is needed to protect and make good use of black soils. At present, the cropping patterns and their spatial characteristics in the black soil region of Northeast China is poorly understood. Based on the crop classification data in 2017-2019, we used geo-information Tupu methods, distribution index model, and bivariate spatial autocorrelation to examine the cropping patterns. The results showed that: 1) The main cropping patterns in the black soil region of Northeast China were continuous maize cropping, continuous rice cropping, continuous soybean cropping, and maize-soybean rotation, accounting for 38.3%, 18.5%, 10.3% and 26.0%, respectively. The maize-soybean rotation included maize-soybean two-year rotation, maize-maize-soybean three-year rotation, and soybean-soybean-maize three-year rotation, accounting for 44.1%, 34.5% and 21.4% of the rotation area, respectively. 2) Various cropping patterns had obviously horizontal differentiation. For instance, continuous maize cropping had very obvious gradient differentiation characteristics in temperature and humidity, but soybean continuous cropping and maize-soybean rotation showed no gradient differentiation, while continuous rice cropping had gradient differentiation only in humidity. 3) Various cropping patterns had obviously spatial clustering characteristics. They had spatial transition characteristics from soybean continuous cropping, soybean-soybean-maize three-year rotation, maize-soybean two-year rotation, maize-maize-soybean three-year rotation, to continuous maize cropping. The cropping pattern in black soil region of Northeast China was dominated by continuous cropping. Understanding its distribution pattern can provide a basis for future spatial optimization of crop rotation.


Asunto(s)
Fabaceae , Oryza , Agricultura/métodos , China , Suelo , Soja , Zea mays
8.
Ying Yong Sheng Tai Xue Bao ; 33(3): 703-710, 2022 Mar.
Artículo en Chino | MEDLINE | ID: mdl-35524522

RESUMEN

Due to the basic topographical characteristics of the gentle and long slope lengths in the Mollisol region of Northeast China, severe soil erosion is easily aggravated by the concentration of surface flow. The spatial distribution of water depth and hydrological connectivity index were introduced to evaluate the effects of typical soil and water conservation practices on the overland flow path and hydrological connectivity based on the GIS and SIMWE (SIMulated Water Erosion) model. We analyzed the effects of different soil and water conservation practices on the hydrological connectivity, water flow path, and spatial distribution of soil erosion and sediment yield by quantifying the variations of soil infiltration rate and surface manning roughness, as well as by constructing an artificial terrain digital elevation model (DEM). The results showed that: 1) terraces could effectively affect the hydrological connectivity of the slope and regulate flow path, with significant differences between the responses of hydrological connectivity and flow path under different forms of terraced fields and ridges. The characteristics of spatial distribution of soil erosion and sediment yield varied with changes in water flow path, which would eventually lead to the intensification of local erosion; 2) practices of vegetated buffer strips and contour tillage presented limited effectiveness on runoff path controlling, though they played a significant role in sediment retention; and 3) conservation tillage could reduce the hydrological connectivity and improve the retention capacity of runoff by increasing surface roughness. This study quantified the effects of different soil and water conservation practices on the hydrological connectivity, flow path, and spatial distribution of soil erosion and sediment yield, and could provide a theoretical reference for scientific layout of soil and water conservation practices in black soil region.


Asunto(s)
Conservación de los Recursos Hídricos , Contaminantes del Suelo , Contaminantes Químicos del Agua , Agricultura , China , Sedimentos Geológicos , Suelo , Erosión del Suelo , Agua
9.
Ying Yong Sheng Tai Xue Bao ; 33(3): 775-783, 2022 Mar.
Artículo en Chino | MEDLINE | ID: mdl-35524531

RESUMEN

Nitrogen limitation is an important factor for the improvement of crop water production potential in rain-fed areas of the Loess Plateau. The reasonable deep application of nitrogen fertilizer is a promising method to increase yield of rain-fed crop. Based on APSIM model, this study simulated spring wheat yield under different nitrogen application rates and depths, by using meteorological observation data from 1990 to 2020 in the semiarid areas of central Gansu Province, aiming to provide theoretical reference for optimizing wheat fertilization strategy. The results showed that the determination coefficient of simulated spring wheat yield, biomass and soil water content in 0-200 cm soil profile was greater than 0.80, the normalized root mean square error was less than 0.2, and the model validity index was greater than 0.5. These results indicated that the model had good fitting and adaptability in the test area. Across all the levels within the experimental design, increasing nitrogen application rates could significantly increase the yield of spring wheat in different precipitation years, and increasing nitrogen application depth could significantly increase spring wheat yield in wet and normal years, but had no effect in dry years. The rate and depth of nitrogen application had significant interaction effects on spring wheat yield in wet and normal years, but not in dry years. According to the binary quadratic regression fitting equation, when the potential maximum yield reached 2749 kg·hm-2 in wet year, nitrogen application depth was 22.7 cm, and nitrogen application rate was 245 kg·hm-2. When the maximum potential yield reached 2596 kg·hm-2 in normal year, nitrogen application depth was 20.6 cm, and nitrogen application rate was 235 kg·hm-2. Integrating the effects of nitrogen application rate and depth on yield, biomass and agronomic efficiency of nitrogen fertilizer, and farmer's fertilizer application habits, the recommended nitrogen application depth was 20-23 cm, and nitrogen application amount was 120-150 kg·hm-2, which could further improve water productivity and nitrogen use efficiency of spring wheat in arid areas of central Gansu Province.


Asunto(s)
Fertilizantes , Nitrógeno , Agricultura/métodos , China , Nitrógeno/análisis , Suelo , Triticum , Agua
10.
Ying Yong Sheng Tai Xue Bao ; 33(3): 784-792, 2022 Mar.
Artículo en Chino | MEDLINE | ID: mdl-35524532

RESUMEN

In this study, we investigated the effects of long-term continuous cucumber cropping on phenolic acids in rhizosphere soil, as well as their link to soil chemical characteristics, enzyme activities, and microbiological activities, using rhizosphere soil from the 2nd, 6th, 10th, 14th, 18th, 20th, 24th, and 26th round of cucumber cultivation in solar greenhouse. The results showed that contents of phenolic acids increased significantly with increasing continuous cropping rounds. The increase amount per round of total phenolic acid was significantly higher in the early stage (0-2 rounds) and late stage (20-26 rounds) than middle stage (10-14 rounds) of continuous cropping. Soil nutrient contents were enriched, while invertase enzyme activity and microbial activities were decreased. Redundancy analysis showed that organic matter, total phosphorus, total nitrogen, available nitrogen, microbial biomass carbon and microbial metabolic entropy were main soil fertility factors correlating with the accumulation of phenolic acids. Results of structural equation model showed that soil phosphorus enrichment directly led to the accumulation of phenolic acids, and that nitrogen enrichment indirectly facilitated the accumulation of phenolic acids by altering the activity of microorganisms. As a result, proper nitrogen and phosphorus fertilizers application would reduce the accumulation of phenolic acids and alleviate the cucumber continuous cropping obstacles.


Asunto(s)
Cucumis sativus , Suelo , Agricultura/métodos , Nitrógeno , Fósforo , Suelo/química , Microbiología del Suelo
11.
Ying Yong Sheng Tai Xue Bao ; 33(3): 793-800, 2022 Mar.
Artículo en Chino | MEDLINE | ID: mdl-35524533

RESUMEN

Soil microorganism is an important indicator of soil health and plays a critical role in biogeochemical processes. We collected soil samples from a multi-year in-situ field experiment with two cropping modes (maize monocropping and maize-potato intercropping) subjected to four nitrogen (N) levels (N0, 0 kg·hm-2; N125, 125 kg·hm-2; N250, 250 kg·hm-2; N375, 375 kg·hm-2). By using the Biolog-ECO microplate method, soil microbial metabolic activity, diversity and utilization of six carbon groups were analyzed. The results showed that N application significantly increased the average well color development (AWCD) values, Simpson and Shannon indices, with the highest value at N250 in mono- and inter-cropped soils. Moreover, N application promoted the utilization of amino acids, amines and phenolic compounds, but decreased the utilization of polymers. Compared with monocropping at the same N level, intercropping improved the AWCD values, Simpson and Shannon indices, with a maximal improvement at N250. Intercropping and nitrogen application significantly affected the metabolic activities of the six carbon-source groups. In addition, intercropping improved the utilization of labile carbon sources, such as amino acids and carbohydrates. Results of the redundancy analysis and linear regression showed that intercropping and N application elevated AWCD values by increasing soil temperature, water content, and soil organic carbon content. Therefore, the changes in soil physicochemical properties after intercropping were the main reason for the enhancement of microbial metabolic activity under N application.


Asunto(s)
Nitrógeno , Suelo , Agricultura/métodos , Aminoácidos/metabolismo , Carbono/metabolismo , Nitrógeno/análisis , Suelo/química , Microbiología del Suelo , Zea mays
12.
Ying Yong Sheng Tai Xue Bao ; 33(3): 801-807, 2022 Mar.
Artículo en Chino | MEDLINE | ID: mdl-35524534

RESUMEN

Drought is one of the main disasters causing agricultural production losses. Accurate and effective agricultural drought monitoring is of great significance to reduce agricultural production losses. In this study, the standardized soil moisture index for agricultural drought evaluation was established by using the historical time series of soil moisture. Based on the index, the temporal and spatial distribution of drought events in the Luanhe River Basin from 2002 to 2019 were analyzed, and the agricultural drought was quantitatively evaluated. The results showed that soil moisture of most grid units in the Luanhe River Basin obeyed normal distribution during the study period, and that the soil moisture of a few grid units obeyed generalized extreme distribution. The changes of drought and flood in each grid unit had good temporal consistency, that is, the changes of drought and flood was consistent. The changes of drought and flood in the middle of the basin was relatively significant, while the agricultural drought generally showed a trend of reduction. The spatial distribution of agricultural drought severity was not obvious. Relatively speaking, the drought characteristics (the frequency, duration and intensity of drought) were higher in the middle and northwest of the basin and lower in the southeast. The results could provide a reference for agricultural drought prediction and the formulation of drought prevention and mitigation measures in the Luanhe River Basin.


Asunto(s)
Sequías , Ríos , Agricultura , Inundaciones , Suelo
13.
Cad Saude Publica ; 38(4): PT165421, 2022.
Artículo en Portugués | MEDLINE | ID: mdl-35508027

RESUMEN

Humans cannot live without water. Whether to quench one's thirst or to supply the foods that humans need, water is always indispensable. Water is present in everything we need to reproduce. From this perspective, the article aims to outline the current state of production and use of water in rural areas in western Santa Catarina State, Brazil, from the perspective of family farmers and leaders of various rural organizations and social movements. We interviewed 30 family farmers from six communities in different micro regions of western Santa Catarina, as well as 20 leaders of social and family farming organizations in the region. The findings included the intense process of contamination of water sources with agricultural pesticides, silting of rivers and creeks, recovery of water production on hillside areas, exponential growth in the use of water from artesian wells to supply farm properties, and microclimatic changes around hydroelectric reservoirs. The study concludes that family farmers have a historical and cultural concern with the availability of water. Still, market demands for crop and livestock produce and the interests of companies that supply pesticides determine the degree of care for water and its preservation. The culture and history of family farming in this region is an ally for Brazilian society that must be protected from dominant agribusiness groups to provide positive responses for preserving water as a precious good and to continue to supply healthier foods.


Não se vive sem água. Seja para saciar a sede, seja para o fornecimento dos alimentos dos quais os seres humanos necessitam, ela sempre é imprescindível. A água é o elemento presente em tudo aquilo que precisamos para nos reproduzir. Nessa perspectiva, este artigo tem como objetivo traçar um panorama atual da produção e da utilização das águas nas áreas rurais da região Oeste Catarinense, Brasil, a partir da visão dos agricultores familiares e das lideranças de diferentes organizações e movimentos sociais do campo. Foram entrevistados 30 agricultores familiares de seis comunidades rurais de diferentes microrregiões do Oeste Catarinense, e 20 lideranças de organizações sociais da agricultura familiar da região. Destacam-se nos resultados: processo intenso de contaminação dos mananciais de água por agrotóxicos utilizados na agricultura; assoreamento de rios e córregos; recuperação da produção de água nas regiões de encostas; crescimento exponencial da utilização de água de poços artesianos no abastecimento das propriedades rurais; e modificações microclimáticas nos entornos dos lagos das hidroelétricas. Conclui-se que a preocupação com a disponibilidade de água, por parte dos agricultores, é histórica e cultural. Contudo são as demandas de mercado por produtos agropecuário e o interesse dos grupos ofertantes de agroquímicos que determinam o cuidado e a preservação. A sociedade tem, na cultura e na história da agricultura familiar regional, uma aliada, que tem de ser protegida do interesse dos grupos dominantes do agronegócio, para ser capaz de dar respostas positivas na preservação deste bem precioso, que é a água, e continuar ofertando alimentos mais saudáveis.


No se vive sin agua. Bien sea para saciar la sed, bien sea para proporcionar los alimentos que los seres humanos necesitan, ella siempre es imprescindible. El agua es el elemento presente en todo aquello que necesitamos para reproducirnos. Desde esa perspectiva, este artículo tiene como objetivo trazar un panorama actual de la producción y de la utilización de las aguas en las áreas rurales de la región oeste del estado de Santa Catarina, Brasil, a partir de la visión de los agricultores familiares y de liderazgos de diferentes organizaciones y movimientos sociales del campo. Se entrevistaron a 30 agricultores familiares de seis comunidades rurales de diferentes microrregiones del oeste catarinense, y a 20 líderes de organizaciones sociales de agricultura familiar de la región. Se destacan en los resultados: proceso intenso de contaminación de los manantiales de agua por pesticidas utilizados en la agricultura; encenagamiento de ríos y arroyos; recuperación de la producción de agua en las regiones de laderas; crecimiento exponencial de la utilización de agua de pozos artesanos para el abastecimiento de las propiedades rurales; y modificaciones microclimáticas en los entornos de los lagos de las hidroeléctricas. Se concluye que la preocupación con la disponibilidad de agua, por parte de los agricultores, es histórica y cultural. No obstante, son las demandas de productos agropecuarios por parte del mercado y el interés de los grupos ofertantes de agroquímicos quienes determinan el cuidado y la preservación. La sociedad tiene en la cultura y en la historia de la agricultura familiar regional una aliada, que tiene que ser protegida del interés de los grupos dominantes del agronegocio, con el fin de sea capaz de dar respuestas positivas a la preservación de este bien precioso, que es el agua, y continuar ofertando alimentos más sanos.


Asunto(s)
Plaguicidas , Agua , Agricultura , Brasil , Humanos , Contaminación del Agua
15.
Science ; 376(6593): 597-603, 2022 05 06.
Artículo en Inglés | MEDLINE | ID: mdl-35511968

RESUMEN

International trade separates consumption of goods from related environmental impacts, including greenhouse gas emissions from agriculture and land-use change (together referred to as "land-use emissions"). Through use of new emissions estimates and a multiregional input-output model, we evaluated land-use emissions embodied in global trade from 2004 to 2017. Annually, 27% of land-use emissions and 22% of agricultural land are related to agricultural products ultimately consumed in a different region from where they were produced. Roughly three-quarters of embodied emissions are from land-use change, with the largest transfers from lower-income countries such as Brazil, Indonesia, and Argentina to more industrialized regions such as Europe, the United States, and China. Mitigation of global land-use emissions and sustainable development may thus depend on improving the transparency of supply chains.


Asunto(s)
Comercio , Gases de Efecto Invernadero , Agricultura , China , Europa (Continente) , Internacionalidad
16.
Ying Yong Sheng Tai Xue Bao ; 33(4): 894-900, 2022 Apr.
Artículo en Chino | MEDLINE | ID: mdl-35543039

RESUMEN

With continuous increases in the amount and duration of plastic film used, the residual film in farmland soil is accumulated and tended to be fragmented, which affects soil water infiltration. We carried out an experiment of one-dimensional vertical infiltration of soil moisture. We examined the effects of different residual film density and area on soil water cumulative infiltration under 21 experimental treatments with 5 residual film area levels (0.25, 0.5, 1, 2, 8 cm2) and 5 residual film density levels (0, 60, 180, 300, 420 kg·hm-2). The results showed that soil water infiltration rate was accelerated and the total infiltration amount was increased by adding a certain amount of residual film into the clay loam soil with bulk density of 1.53 g·cm-3. The total infiltration amount of different residual film area always appeared mutation or turning point when the single residual film area was 1 cm2. When the residual film area and density were larger or smaller than that, the cumulative infiltration amount would be significantly affected, with the treatment of 0.5 cm2 residual film area and 200 kg·hm-2 residual film density being obvious demarcation. When the residual film area was 0.25 cm2, the cumulative infiltration reached the maximum. When the residual film with a single area ≤0.25 cm2 was uniformly mixed into the soil, the slope of soil water cumulative infiltration curve was significantly different from that of other residual film treatments, forming a "new structure" soil with unique water infiltration characteristics.


Asunto(s)
Suelo , Agua , Agricultura/métodos , China , Plásticos , Agua/análisis
17.
Ying Yong Sheng Tai Xue Bao ; 33(4): 1021-1026, 2022 Apr.
Artículo en Chino | MEDLINE | ID: mdl-35543055

RESUMEN

The new large-grained activated humic acid fertilizer (LAF) can significantly reduce the amount of chemical fertilizer application and stable fruit yield. Understanding its impacts on soil aggregates and organic carbon is an important basis for revealing its role in driving soil structure of apple orchard. There were four LAF treatments: LAF1 (full fertilization, fertilization period and mass ratio (the same below), germination stage: fruit expansion stage: maturity stage=3:4:3), LAF2 (full fertilization, germination stage: fruit expansion stage: maturity stage=2:3:5), LAF3 (fertilizer application reduction by 1/4, germination stage: fruit expansion stage: maturity stage=2:3:5), LAF4 (fertilizer application reduction by 1/3, germination stage: fruit expansion stage: maturity stage=2:3:5); with no fertilization as control (CK). In a four-year pot experiment, we examined the composition, stabi-lity and organic carbon content of soil aggregates under different fertilization treatments. The results showed that: 1) compared with CK, each treatment of LAF increased the content of >2 mm and 2-0.25 mm aggregate by 53.4%-77.5% and 12.3%-17.0%, respectively. The application of LAF significantly increased the content of soil water stable aggregates, and such effects were positively related with application amount. The content of soil water stable aggregate was the highest in the LAF1 treatment. 2) There was no significant difference in aggregate content of each particle size among LAF treatments, with the proportion of aggregate content of 2-0.25 mm particle size being the highest. 3) Compared with CK, all LAF treatments significantly increased the average weight diameter (MWD) and geometric mean diameter (GMD), and reduced the fractal dimension (D). LAF1 treatment had the highest MWD and GMD values, and had the strongest effect on the stability of soil aggregates. 4) Except for LAF4 treatment, the content of soil organic carbon in other LAF treatments was significantly higher than that in CK, and the content of soil organic carbon in LAF2 treatment was the highest. All LAF treatments increased the organic carbon content of soil aggregates with each particle size. LAF1, LAF2, and LAF3 treatments significantly increased the organic carbon of aggregates with particle size >2 mm. Particle size >2 mm had the highest contribution to the total organic carbon. The contribution rate of water stable large aggregate organic carbon to total organic carbon of LAF treatment was significantly higher than that of CK, which was all higher than 66.0%, and that of LAF1 treatment was the highest. In conclusion, the application of LAF enhanced the formation and stability of water stable aggregates and increased organic carbon content of aggregates in apple orchard soil, with the best performance of the full application. The application of LAF could be used as an effective measure to improve soil structure and fertility in apple orchard.


Asunto(s)
Fertilizantes , Malus , Agricultura , Carbono/análisis , China , Sustancias Húmicas , Suelo/química , Agua
18.
Ying Yong Sheng Tai Xue Bao ; 33(4): 1027-1036, 2022 Apr.
Artículo en Chino | MEDLINE | ID: mdl-35543056

RESUMEN

We examined the effects of biochar and urease inhibitors/nitrification inhibitors on nitrification process, ammonia and N2O emission in subtropical soil, and determined the best combination of biochar with nitrification and urease inhibitors. This work could provide a theoretical basis for the mitigation of the negative environmental risk caused by reactive nitrogen gas in the application of nitrogen fertilizer. A indoor aerobic culture test was conducted with seven treatments [urea+biochar (NB), urea+nitrification inhibitor (N+NI), urea+urease inhibitor (N+UI), urea+nitrification inhibitor+urease inhibitor (N+NIUI), urea+nitrification inhibitor+biochar (NB+NI), urea+urease inhibitor+biochar (NB+UI), urea+nitrification inhibitor+urease inhibitor+biochar (NB+NIUI)] and urea (N) as the control. The dynamics of soil inorganic nitrogen content, N2O emission and the volatility of ammonia volatilization were observed under combined application of biochar with urease inhibitor (NBPT)/nitrification inhibitor (DMPP). The results showed that:1)Compared to the control (5.11 mg N·kg-1·d-1) during the incubation period, NB treatment significantly increased therate constant of nitrification by 33.9%, and N+NI treatment significantly reduced the nitrification rate constant by 22.9%. NB treatment significantly increased the abundance of ammonia oxidizing bacteria (AOB) by 56.0%. 2) Compared with N treatment, N+NI and NB+NI treatments signi-ficantly enhanced the cumulative emission of NH3 by 49%. The N+UI treatment reduced the cumulative loss of NH3. The inhibition effect of NB+UI treatment was more significant. 3) The emission rate of N2O was highest in the first 10 days after fertilization. The N2O emission under NB treatment was the earliest, and that of N treatment was the highest (5.87 µg·kg-1·h-1). The combined application of DMPP and NBPT performed the best in reducing soil N2O emission. We estimated global warming potential (GWP) of the direct N2O and indirect N2O (NH3) emissions. Compared with N treatments, N+NI and NB+NI treatments increased the GWP by 34.8% and 40.9%, respectively. While the NB and NB+UI treatments significantly reduced the GWP by 45.9% and 60.5%, the combination of biochar and urease inhibitor had the best effect on reduction of GWP of soil active nitrogen emissions.


Asunto(s)
Nitrificación , Suelo , Agricultura/métodos , Amoníaco/análisis , Carbón Orgánico , Yoduro de Dimetilfenilpiperazina/farmacología , Fertilizantes/análisis , Nitrógeno/análisis , Óxido Nitroso/análisis , Urea , Ureasa
19.
Ying Yong Sheng Tai Xue Bao ; 33(4): 1037-1044, 2022 Apr.
Artículo en Chino | MEDLINE | ID: mdl-35543057

RESUMEN

In order to optimize water and fertilizer use in the double-cropping rice in eastern Fujian Province, a field runoff plot experiment was conducted to investigate rice yield, nutrient uptake, and runoff losses of N (nitrogen) and P (phosphorus) in the T0(no chemical fertilization with traditional flooding irrigation), T1(common chemical fertilizer of 273 kg N·hm-2, 59 kg P·hm-2, and 112 kg K·hm-2 combined with traditional flooding irrigation), T2(chemical fertilizer of 240 kg N·hm-2, 52 kg P·hm-2, and 198 kg K·hm-2 combined with traditional flooding irrigation) and T3(chemical fertilizer combined with shallow intermittent irrigation) treatments. Results showed that early rice grain yield in the T1, T2 and T3 treatments significantly increased by 0.7, 1.0, 1.1 times, late rice grain yield significantly increased by 0.9, 1.1, 1.0 times compared to that in the T0 treatment, respectively. The T1, T2 and T3 treatments significantly increased the uptake of N and P in aboveground parts of the plants, especially in grains. The T1, T2 and T3 treatments significantly increased N uptake by 1.1, 1.2, 1.2 times, increased P uptake by 0.9, 1.4, 1.6 times in early-season grains, and significantly increased N uptake by 0.8, 1.0, 1.0 times, increased P uptake by 0.7, 0.9, 0.9 times in late-season grains, compared to T0, respectively. Furthermore, T3 increased agronomic N use efficiency (AEN) and agronomic P use efficiency (AEP) by 71.1% and 69.2% in early rice plants, increased AEN and AEP by 26.4% and 25.0% in late rice plants, whereas T3 decreased total dissolved N (DN) by 16.0% in comparison with T1. Dissolved inorganic N loss in surface runoff occurred mainly in the form of NO3--N (nitrate N) under different water and fertilizer regimes. However, there were no significant differences in AEN and AEP between T2 and T3 treatments. These findings suggested that optimal applications of water and fertilizers (T3) might increase N and P uptake in rice plants, maintain yield, and reduce N loss, especially in the form of NO3--N in surface water from early rice field. In general, this study could provide theoretical support for the optimization of irrigation and fertilization and for the control of N and P non-point source pollution from the double cropping rice paddy fields in eastern Fujian Province.


Asunto(s)
Oryza , Fósforo , Agricultura/métodos , China , Fertilización , Fertilizantes , Nitrógeno/análisis , Fósforo/análisis , Suelo , Agua
20.
PLoS One ; 17(5): e0266904, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35536832

RESUMEN

In order to explore the sustainable growth of Chinese agriculture, this paper assesses how the heterogeneous SPS measures affect China's growth margins and quality upgrading in the agricultural sector. We estimate improved gravity-model that exploit the cross-country differences in SPS measures over the period from 2000 to 2014. Our findings show that the heterogeneous SPS measures restrict the intensive margin and extensive margin, but significantly promote the product quality-even with no significant effect on price index. Conditional on quality upgrading, the heterogeneous SPS measures decrease the extent of quality upgrading. On one hand, because of cross-country differences in SPS standards, standards from developed countries have less effective trade effect on China's agri-products export quality upgrading; On the other hand, because of cross-firm differences in the ability to deal with SPS standards, the laggards in China have the higher probability to switch to lower entrance barrier countries. Therefore, it is possible for China to trap in the low-quality agricultural growth in the long term.


Asunto(s)
Agricultura , China
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...