Livestock rearing is one of the major occupations in India and is making significant contribution to the country GDP. The regional and seasonal variations in the teperature and rainfall distribution have been the majo...Livestock rearing is one of the major occupations in India and is making significant contribution to the country GDP. The regional and seasonal variations in the teperature and rainfall distribution have been the major factors influencing the economy of a region. It is a matter of serious concern that out of 11 districts of central India, 9 districts are showing increasing trend in maximum temperature with a rate of 0.01°C to 0.15°C/year. A significant long-term decreasing trend (Slope = -4.26) was found in annual rainfall series at Jhansi. At Jhansi, moderate to severe drought occurs once in five years. But in the last decade, 7 years experienced moderate to disastrous drought in Jhansi region, wherein rainfall deficiency ranged between 40% and 60% from normal value. Of special mention was the year, 2006, which experienced a worst drought ever recorded for this region. Studies related to crop simulation model was carried out for fodder sorghum and its application for agronomic management and assessing the impact of climate change. Crop modeling studies on forage sorghum (C4) and cowpea (C3) showed increased dry matter biomass by 3% in sorghum but more prominent in cowpea by 46% under elevated CO2 from 330 ppm to 770 ppm. The interaction study of enhanced CO2 and temperature showed prominent negative impact on yields of both the crops. Evapotranspiration and crop coefficient (Kc) of several fodder crops i.e. berseem, lucerne, oat, sorghum, teosinte, maize + cowpea, guinea + berseem were worked out. In berseem, the highest Kc (1.81) was found during 2nd cutting followed by 3rd and 4th cuts. Estimates on irrigation scheduling for the guinea grass + berseem showed that the cropping system requires 7 irrigations at an interval ranging from 13 to 30 days to fulfill the 567.6 mm of water per season as net irrigation under mar soil (black) type whose actual water holding capacity (AWHC) is 175 mm. Similarly, if the cropping system is grown under kabar (AHWC = 140 mm) soil, then it requires nine irrigation with a total water requirement of 591.5 mm at an interval ranging from 10 to 24 days. For integrated pest management (IPM) scheme of lucerne, degree day based model was developed to monitor the lucerne weevil population in central region.展开更多
Different crops need different kinds of nutrients. In this paper,formula of special fertilizer for common field crops in Guangxi is explored from the angle of grain crops,fruits,vegetables,sugar crops,oil crops,etc.,a...Different crops need different kinds of nutrients. In this paper,formula of special fertilizer for common field crops in Guangxi is explored from the angle of grain crops,fruits,vegetables,sugar crops,oil crops,etc.,and corresponding production equipment and methods are provided,which could convenience for agricultural precision fertilization and theoretical basis and technical reference for cost saving and efficiency increasing of fertilizer.展开更多
Studies on peri urban farming in Zambia have not adequately tackled the issues pertaining to heavy metal contaminated wastewater irrigation farming. The study investigated heavy metal contamination of water, soils and...Studies on peri urban farming in Zambia have not adequately tackled the issues pertaining to heavy metal contaminated wastewater irrigation farming. The study investigated heavy metal contamination of water, soils and crops at two peri urban areas in Zambia. Two study sites were New Farm Extension in Mufulira Town in the Copperbelt Province and Chilumba Gardens in Kafue Town in Lusaka Province. The heavy metals investigated were lead, copper, cobalt, nickel and chromium. These heavy metals were found to be higher than acceptable limits in wastewater used to irrigate crops and there are potential human health risks associated with consumption of heavy metal contaminated food crops which have implications on the livelihoods of people. Samples of water, soil and crops were collected and analysed for lead (Pb), copper (Cu), chromium (Cr), cobalt (Co) and nickel (Ni) using the Atomic Absorption Spectrometer (AAS). The data on heavy metals was analysed using mean, standard error and T-test. The results indicated that the levels of heavy metals in wastewater, soil and food crops were above acceptable limits at two study sites. It can be concluded that there was heavy metal contamination of wastewater, soil and food crops at the two peri-urban areas in Zambia. The study highlighted the actual levels of heavy metal contaminant uptake in food crops consumed by the peri urban population. The information from this study can be used by the relevant authorities to develop appropriate measures for monitoring and control of heavy metal contamination in wastewater irrigation farming systems in peri urban areas inZambia.展开更多
Ability to modify plants at the genomic level by advanced molecular technology has enhanced the scope of improvements in plant traits attempted earlier through conventional breeding methods. Techniques such as genetic...Ability to modify plants at the genomic level by advanced molecular technology has enhanced the scope of improvements in plant traits attempted earlier through conventional breeding methods. Techniques such as genetic transformation have opened new vistas whereby functional genes, not commonly present in a particular species can be added from other species. The traits incorporated into the genetically engineered plants in the beginning were confined to those governed by dominant genes, e.g. insecticide resistance and herbicide tolerance but advancements with time now also permit the transfer of complexly inherited traits such as drought and cold tolerance. Transgenic technology is also useful in understanding gene expression and metabolic pathways which can then be used to harness the full genomic potential of the plant. This review presents a narrative on development of transgenics and their use for the improvement of field, industrial and pharmaceuticals crops. In addition, discussions are made on current status on genetically modified crops, hurdles to genetic engineering, overcoming strategies and future scope.展开更多
S?o Paulo State is the main sugar cane producer and these agricultural activities are carried out in predominantly sandy soils, which require large amounts of phosphate fertilizers and amendments. This work evaluated ...S?o Paulo State is the main sugar cane producer and these agricultural activities are carried out in predominantly sandy soils, which require large amounts of phosphate fertilizers and amendments. This work evaluated the fertilizer-effect on the Al, Ba, Fe, Mn and Ni released in a watershed with influence of sugar cane crops in the S?o Paulo State, Brazil, namely the Monjolo Grande Stream basin. Five surface water sampling campaigns were carried out at the mouth of Monjolo Grande Stream in February, April, June, September and November 2010, characterizing the following parameters: discharge, pH, temperature, electric conductivity, dissolved oxygen and total and dissolved concentrations of Al, Ba, Fe, Mn and Ni. Approximately 99% of Al and Fe are transported annually in association with suspended sediments carried to the Monjolo Grande Stream by sheet erosion. The results also demonstrated that the increasing Al, Ba, Fe and Mn concentrations dissolved in the waters of the Monjolo Grande Stream basin in the wet season are associated to phosphate fertilizers and amendments that are used extensively in agrichemical activities. However, with the current application rates, there has been no increase in the dissolved concentrations of these metals at levels that could pose risks to human health.展开更多
Monitoring agricultural drought using remote sensing data is crucial for precision irrigation in modern agriculture.Utilizing unmanned aerial vehicle(UAV)remote sensing,we explored the applicability of an empirical cr...Monitoring agricultural drought using remote sensing data is crucial for precision irrigation in modern agriculture.Utilizing unmanned aerial vehicle(UAV)remote sensing,we explored the applicability of an empirical crop water stress index(CWSI)based on canopy temperature and three-dimensional drought indices(TDDI)constructed from surface temperature(T_(s)),air temperature(T_(a))and five vegetation indices(VIs)for monitoring the moisture status of dryland crops.Three machine learning algorithms(random forest regression(RFR),support vector regression,and partial least squares regression)were used to compare the performance of the drought indices for vegetation moisture content(VMC)estimation in sorghum and maize.The main results of the study were as follows:(1)Comparative analysis of the drought indices revealed that T_(s)-T_(a)-normalized difference vegetation index(TDDIn)and T_(s)-T_(a)-enhanced vegetation index(TDDIe)were more strongly correlated with VMC compared with the other indices.The indices exhibited varying sensitivities to VMC under different irrigation regimes;the strongest correlation observed was for the TDDIe index with maize under the fully irrigated treatment(r=-0.93).(2)Regarding spatial and temporal characteristics,the TDDIn,TDDIe and CWSI indices showed minimal differences Over the experimental period,with coefficients of variation were 0.25,0.18 and 0.24,respectively.All three indices were capable of effectively characterizing the moisture distribution in dryland maize and sorghum crops,but the TDDI indices more accurately monitored the spatial distribution of crop moisture after a rainfall or irrigation event.(3)For prediction of the moisture content of single crops,RFR models based on TDDIn and TDDIe estimated VMC most accurately(R^(2)>0.7),and the TDDIn-based model predicted VMC with the highest accuracy when considering multiple-crop samples,with R^(2)and RMSE of 0.62 and 14.26%,respectively.Thus,TDDI proved more effective than the CWSI in estimating crop water content.展开更多
Traditional transgenic detection methods require high test conditions and struggle to be both sensitive and efficient.In this study,a one-tube dual recombinase polymerase amplification(RPA)reaction system for CP4-EPSP...Traditional transgenic detection methods require high test conditions and struggle to be both sensitive and efficient.In this study,a one-tube dual recombinase polymerase amplification(RPA)reaction system for CP4-EPSPS and Cry1Ab/Ac was proposed and combined with a lateral flow immunochromatographic assay,named“Dual-RPA-LFD”,to visualize the dual detection of genetically modified(GM)crops.In which,the herbicide tolerance gene CP4-EPSPS and the insect resistance gene Cry1Ab/Ac were selected as targets taking into account the current status of the most widespread application of insect resistance and herbicide tolerance traits and their stacked traits.Gradient diluted plasmids,transgenic standards,and actual samples were used as templates to conduct sensitivity,specificity,and practicality assays,respectively.The constructed method achieved the visual detection of plasmid at levels as low as 100 copies,demonstrating its high sensitivity.In addition,good applicability to transgenic samples was observed,with no cross-interference between two test lines and no influence from other genes.In conclusion,this strategy achieved the expected purpose of simultaneous detection of the two popular targets in GM crops within 20 min at 37°C in a rapid,equipmentfree field manner,providing a new alternative for rapid screening for transgenic assays in the field.展开更多
Hail is one of meteorological disasters affecting crop growth in Ulanqab City.It happens frequently from May to September,and this period is also the main growing season of crops.In this period,hail will cause damage ...Hail is one of meteorological disasters affecting crop growth in Ulanqab City.It happens frequently from May to September,and this period is also the main growing season of crops.In this period,hail will cause damage to crops,make farmland soil harden,and bring varying degrees of harm to agricultural production.Artificial hail suppression is an important scientific and technological means for disaster prevention and mitigation.It is necessary to strengthen the monitoring,analysis and forecast of severe convection weather,intensify the release of early warning information of hail weather,provide accurate and reliable real-time information for the implementation of artificial hail suppression operations,strengthen the implementation of artificial weather modification,effectively carry out artificial hail suppression operations,and avoid and reduce the impact of hail disaster.展开更多
Rising atmospheric CO2 levels pose many challenges to global climate, thus to all forms of life including plants. The impact of elevated CO2 on plant growth and development and the nutritional quality in relation to m...Rising atmospheric CO2 levels pose many challenges to global climate, thus to all forms of life including plants. The impact of elevated CO2 on plant growth and development and the nutritional quality in relation to major nutrients in many crops has been explored extensively. However, information on the elevated CO2 effects on the health-promoting phytochemicals in food crops is rather limited. Major nutrients in food crops including protein, phosphorus, potassium, calcium, iron, zinc and other micronutrients in many food crops are known to be suppressed at elevated CO2 levels. Elevated CO2 increases carbohydrate accumulation but decreases nitrogen accumulation in plants thus affecting their C-N ratio. A number of studies show that high C-N ratio and nitrogen limiting conditions in plants can result in the accumulation of carbon-based secondary metabolites, many of which are health-promoting phytochemicals and allelochemicals involved in plants’ defense against pathogens and herbivory. Although the results from these studies are variable, it can be concluded that while elevated CO2 is known to suppress the content of major nutrients, it may actually have a favorable impact on the accumulation of carbon-based phytochemicals in food crops.展开更多
Typical row-crop agricultural practices can potentially be harmful to soil health and future sustainability. The use of cover crops (CC) as a mechanism to improve soil health on a wide scale remains underutilized. Soi...Typical row-crop agricultural practices can potentially be harmful to soil health and future sustainability. The use of cover crops (CC) as a mechanism to improve soil health on a wide scale remains underutilized. Soil health remains a major concern for the sustainability of agricultural productivity, therefore, research into CC implementation as a mean to preserve or improve soil health is warranted. The objective of this study was to evaluate the effects of CC on the soils in the eastern Arkansas portion of the Lower Mississippi River Valley (LMRV) over time for various chemical soil parameters, including pH, soil organic matter (SOM), soil elemental contents (i.e., P, K, Ca, Mg, S, Na, Fe, Mn, Zn, Cu, and B), soil respiration, and a generalized soil health score index. Soil pH decreased over time under both CC and no-cover-crop (NCC) treatments, by −0.3 and −0.2, respectively. Soil OM decreased over time under NCC by −0.1%, but did not differ between CC treatments. Soil N availability decreased over time under NCC (−22.6 kg·ha−1), but did not change over time under CC. Soil respiration decreased over time under both CC and NCC, by −76.1 mg·L−1 and −77.3 mg·L−1, respectively, though there was no effect of CC treatment. The Haney soil health score index decreased under CC (−7.0) and NCC (−6.8) without an effect from CC treatment. Results of the study place emphasis on the temporal nature of soil health as influenced by cover crops and their potential to improve soil health.展开更多
It is ordinarily common for forage production in southern Kyushu to adopt a double cropping system, composed of summer forage crops (e.g. maize and sorghum) cultivated from late March to early September, and winter gr...It is ordinarily common for forage production in southern Kyushu to adopt a double cropping system, composed of summer forage crops (e.g. maize and sorghum) cultivated from late March to early September, and winter grass crops (e.g. Italian ryegrass (IR) and oat) from mid-October to the following May. However, if high total digestible nutrient (TDN) production is aimed to introduce winter cereal crops (e.g. wheat and barley) as a replacement of IR, it is necessary to cultivate tropical grass, which has a rapid-growth potential with high crude protein (CP) concentration in a switching period between summer and winter crops. In this study, teff (Eragrostis tef) was tried to evaluate as a candidate crop in the switching period. Yield and quality of two types of triple forage cropping system were determined under maize-teff-barley and maize-teff-wheat in the first and second year, respectively. Compared with the normal year, summer temperature was higher and summer and winter precipitations were lower in the first year, while no climatic disorder was observed in the second year. Even though dry matter yield of teff was minimal in the present system due to weed damage, CP concentration was the highest among crops and TDN yields of the present cropping system tended to be higher in the second year with no drought stress than in the conventional maize-IR system in the region.展开更多
This research presented a mathematical model to calculate the consumption of diesel oil and the respective emissions of CO2from 41 agricultural crops (38 permanent and 3 temporary) in Brazil. It contains data obtain...This research presented a mathematical model to calculate the consumption of diesel oil and the respective emissions of CO2from 41 agricultural crops (38 permanent and 3 temporary) in Brazil. It contains data obtained between 2000 and 2012, from accreditedbibliographic sources. In addition to spreadsheets containing diesel consumption, resulting from the analysis of the productive processes,this research presents data on energy conversion and forest development used to subsidize CO2 emissions and mitigation options.Specifically for C sequestration of the atmosphere, four options of forest projects were systematized: (1) reforestation with fast growingspecies; (2) forest protection projects, with enrichment plantations; (3) implementation of agroforestry systems (1 st cycle); and (4) urbanafforestation projects (streets and parks). Such alternatives are in line with the proposals of the "sectorial plan for mitigation andadaptation to climate change for the consolidation of a low C emission in agriculture", of the Brazilian Agricultural ResearchCorporation (EMBRAPA). The results show that three temporary products (soybean, sugarcane and cotton) are responsible, for at least,85% of all CO2 emissions, comparatively the low consumption of diesel oil verified in the management of the 38 permanent productsstudied in this research. Therefore, in order to contribute to the reduction of the release of CO2 into the atmosphere, perennial crops andecologically rational extractivism should be more encouraged and more supported by the public authorities.展开更多
Genetically Modified Crops (GMCs) and Climate Change (CC) are the two most contentious ecological issues the world faces today. Application of transgenics in agriculture is most debated because of its direct and indir...Genetically Modified Crops (GMCs) and Climate Change (CC) are the two most contentious ecological issues the world faces today. Application of transgenics in agriculture is most debated because of its direct and indirect implications. The advertized benefits in the backdrop of the potentially harmful effects on health and environment make this an issue of greater concern. On the other hand, Climate Change is a problem of enormous scale and its after-effects even more grave. The impact of climate change on agriculture, though well researched, is still very uncertain. Further, the introduction and global embrace of a technology with unverified credentials may prove to be an ill-conceived and ill-timed act. The future of GMC technology in India will be both challenging as well as exciting. Therefore any decision on this front should be taken with scientific rigor and logic. Our aim is to explore this complex inter-relationship and provide impetus for further research.展开更多
Nitrate (NO3) leaching is a major issue in sandy soils intensively cropped to potato. Modelling could test the effect of management practices on nitrate leaching, particularly with regard to optimal N application rate...Nitrate (NO3) leaching is a major issue in sandy soils intensively cropped to potato. Modelling could test the effect of management practices on nitrate leaching, particularly with regard to optimal N application rates. The NO3 concentration in the soil solution is well known for its local heterogeneity and hence represents a major challenge for modeling. The objective of this 2-year-study was to evaluate machine learning regression methods to simulate seasonal NO3 concentration dynamics in suction lysimeters in potato plots receiving different N application rates. Four machine learning function approximation methods were compared: multiple linear regressions, multivariate adaptive regression splines, multiple-layer perceptrons, and least squares support vector machines. Input candidates were chosen for known relationships with NO3 concentration. The best regression model was obtained with a 6-inputs least squares support vector machine combining cumulative rainfall, cumulative temperature, day of the year, N fertilisation rate, soil texture, and depth.展开更多
Cover crops can provide changes in soil chemical and physical properties, which could allow a sustainable development of soybean and upland rice rotation in Brazilian Cerrado. The objective of this study was to determ...Cover crops can provide changes in soil chemical and physical properties, which could allow a sustainable development of soybean and upland rice rotation in Brazilian Cerrado. The objective of this study was to determine the effects of cover crops(cultivated in the offseason) in the soybean-upland rice rotation(cultivated in the summer season) on the soil chemical and physical properties, yield components and grain yield of the cash crops. The experimental design was a randomized block design in factorial scheme 4 × 2 with six replications. Treatments were composed by four cover crops: fallow, millet(Pennisetum glaucum) + Crotalaria ochroleuca, millet + pigeon pea(Cajanus cajans), and millet + pigeon pea + Urochola ruziziensis in the offseason with one or two cycles of cover crops, with rice(Oryza sativa)or soybean(Glycine max) in the summer season. Cover crops alone provided no changes in soil chemical properties. However, the rotation cover crops/cash crops/cover crops/cash crops reduced p H, Al and H + Al and increased Ca, Mg, K and Fe contents in the soil. The cover crops millet + pigeon pea and millet + pigeon pea + U. ruziziensis improved soil physical properties in relation to fallow,especially in the 0–0.10 m soil layer. In spite of the improvement of the soil physical properties after two years of rotation with cover crops and cash crops, the soil physical quality was still below the recommended level, showing values of macroporosity, S index and soil aeration capacity lower than 0.10 m3/m3, 0.035 and 0.34, respectively. Upland rice production was higher under mixtures of cover crops than under fallow, mainly because of soil physical changes done by these mixtures of cover crops.Soybean grain yield was similar under all cover crops tested, but was higher after the rotation cover crops/upland rice/cover crops than after only one cycle of cover crops.展开更多
Cover crops are the plants which are grown to improve soil fertility, prevent soil erosion, enrichment and protection of soil, and enhance nutrient and water availability, and quality of soil. Cover crops provide seve...Cover crops are the plants which are grown to improve soil fertility, prevent soil erosion, enrichment and protection of soil, and enhance nutrient and water availability, and quality of soil. Cover crops provide several benefits to soils used for agriculture production. Cover crops are helpful in increasing and sustaining microbial biodiversity in soils. We summarized the effect of several cover crops in soil properties such as soil moisture content, soil microbial activities, soil carbon sequestration, nitrate leaching, soil water, and soil health. Selection of cover crops usually depends on the primary benefits which are provided by cover crops. Other factors may also include weather conditions, time of sowing, either legume or non-legume and timing and method of killing of a cover crop. In recent times, cover crops are also used for mitigating climate change, suppressing weeds in crops and increasing exchangeable nutrients such as Mg2+ and K+. Cover crops are also found to be economical in long-term experiment studies. Although some limitations always come with several benefits. Cover crops have some problems including the method of killing, host for pathogens, regeneration, and not immediate benefits of using them. Despite the few limitations, cover crops improve the overall health of the soil and provide a sustainable environment for the main crops.展开更多
Production of energy crops is perceived as a potential source of alternative energy for petroleum oil. However, it is cru-cial to ensure that there is adequate land and water available for production of energy crops b...Production of energy crops is perceived as a potential source of alternative energy for petroleum oil. However, it is cru-cial to ensure that there is adequate land and water available for production of energy crops before indulging into the business of producing such crops. This paper assesses the availability of land and water resources for production of energy crops in the SADC region using landuse/landcover data, hydrological and meteorological data, as well as socioeconomic data. It is found that Botswana and Mozambique have large amounts of bushland that can be used for expansion of agricultural land including production of energy crops. Zimbabwe has the highest amount of land under cultivation, which makes it difficult for the country to expand its agricultural land. However, land reform processes taking place in Zimbabwe provides a good opportunity to diversify agricultural production including reallocation of farms for production of energy crops. Mozambique has favorable rainfall for production of maize and sugarcane, whereas Zimbabwe can explore growing Jatropha on degraded land and use irrigation for cultivation of sugarcane. High frequency of crop failure in Botswana makes it difficult to grow maize or sugarcane as energy crop. The country can promote production of sweet sorghum, which is traditionally grown by small scale farmers, and explore production of Jatropha in degraded and desert land. A regional approach to address land and water requirements for production of energy crops is considered important as compared to planning for production in each country as the constraints and potential of each country can be fully recognized. More detailed country specific research is needed on the production of the specified energy crops to ensure sustainability of the production systems.展开更多
The long-term success of hydrogenase uptake negative legume-rhizobia associations, in spite of their apparent inefficiency, may be explained by the positive effects of H2 release to soil. A primary benefit of H2 relea...The long-term success of hydrogenase uptake negative legume-rhizobia associations, in spite of their apparent inefficiency, may be explained by the positive effects of H2 release to soil. A primary benefit of H2 release to soil is the stimulation of H2-oxidizing, plant growth promoting rhizobacteria (PGPR) [1]. Two such previously isolated strains were tested as seed inoculants for barley and spring wheat;there were significant differences between treatments and controls in tiller and grain head production, supported by data from greenhouse trials. T-RFLP analysis of barley soil samples, supported by DNA sequencing data, successfully distinguished both species inoculated. Successful re-isolation indicates that these isolates can reproduce themselves in soils and can be used as effective inoculants with peat as the standard carrier. This study showed that we are able to achieve some of the beneficial effects of crop rotation without the need to implement actual crop rotation.展开更多
Nitrogen(N)is a key factor in the positive response of cereal crops that follow leguminous crops when compared to gramineous crops in rotations,with the nonrecyclable rhizosphere-derived N playing an important role.Ho...Nitrogen(N)is a key factor in the positive response of cereal crops that follow leguminous crops when compared to gramineous crops in rotations,with the nonrecyclable rhizosphere-derived N playing an important role.However,quantitative assessments of differences in the N derived from rhizodeposition(NdfR)between legumes and gramineous crops are lacking,and comparative studies on their contributions to the subsequent cereals are scarce.In this study,we conducted a meta-analysis of NdfR from leguminous and gramineous crops based on 34 observations published worldwide.In addition,pot experiments were conducted to study the differences in the NdfR amounts,distributions and subsequent effects of two major wheat(Triticum aestivum L.)-preceding crops,corn(Zea mays L.)and soybean(Glycine max L.),by the cotton wick-labelling method in the main wheat-producing areas of China.The meta-analysis results showed that the NdfR of legumes was significantly greater by 138.93%compared to gramineous crops.In our pot experiment,the NdfR values from corn and soybean were 502.32 and 944.12 mg/pot,respectively,and soybean was also significantly higher than corn,accounting for 76.91 and 84.15%of the total belowground nitrogen of the plants,respectively.Moreover,in different soil particle sizes,NdfR was mainly enriched in the large macro-aggregates(>2 mm),followed by the small macro-aggregates(2–0.25 mm).The amount and proportion of NdfR in the macro-aggregates(>0.25 mm)of soybean were 3.48 and 1.66 times higher than those of corn,respectively,indicating the high utilization potential of soybean NdfR.Regarding the N accumulation of subsequent wheat,the contribution of soybean NdfR to wheat was approximately 3 times that of corn,accounting for 8.37 and 4.04%of the total N uptake of wheat,respectively.In conclusion,soybean NdfR is superior to corn in terms of the quantity and distribution ratio of soil macro-aggregates.In future field production,legume NdfR should be included in the nitrogen pool that can be absorbed and utilized by subsequent crops,and the role and potential of leguminous plants as nitrogen source providers in crop rotation systems should be fully utilized.展开更多
文摘Livestock rearing is one of the major occupations in India and is making significant contribution to the country GDP. The regional and seasonal variations in the teperature and rainfall distribution have been the major factors influencing the economy of a region. It is a matter of serious concern that out of 11 districts of central India, 9 districts are showing increasing trend in maximum temperature with a rate of 0.01°C to 0.15°C/year. A significant long-term decreasing trend (Slope = -4.26) was found in annual rainfall series at Jhansi. At Jhansi, moderate to severe drought occurs once in five years. But in the last decade, 7 years experienced moderate to disastrous drought in Jhansi region, wherein rainfall deficiency ranged between 40% and 60% from normal value. Of special mention was the year, 2006, which experienced a worst drought ever recorded for this region. Studies related to crop simulation model was carried out for fodder sorghum and its application for agronomic management and assessing the impact of climate change. Crop modeling studies on forage sorghum (C4) and cowpea (C3) showed increased dry matter biomass by 3% in sorghum but more prominent in cowpea by 46% under elevated CO2 from 330 ppm to 770 ppm. The interaction study of enhanced CO2 and temperature showed prominent negative impact on yields of both the crops. Evapotranspiration and crop coefficient (Kc) of several fodder crops i.e. berseem, lucerne, oat, sorghum, teosinte, maize + cowpea, guinea + berseem were worked out. In berseem, the highest Kc (1.81) was found during 2nd cutting followed by 3rd and 4th cuts. Estimates on irrigation scheduling for the guinea grass + berseem showed that the cropping system requires 7 irrigations at an interval ranging from 13 to 30 days to fulfill the 567.6 mm of water per season as net irrigation under mar soil (black) type whose actual water holding capacity (AWHC) is 175 mm. Similarly, if the cropping system is grown under kabar (AHWC = 140 mm) soil, then it requires nine irrigation with a total water requirement of 591.5 mm at an interval ranging from 10 to 24 days. For integrated pest management (IPM) scheme of lucerne, degree day based model was developed to monitor the lucerne weevil population in central region.
文摘Different crops need different kinds of nutrients. In this paper,formula of special fertilizer for common field crops in Guangxi is explored from the angle of grain crops,fruits,vegetables,sugar crops,oil crops,etc.,and corresponding production equipment and methods are provided,which could convenience for agricultural precision fertilization and theoretical basis and technical reference for cost saving and efficiency increasing of fertilizer.
文摘Studies on peri urban farming in Zambia have not adequately tackled the issues pertaining to heavy metal contaminated wastewater irrigation farming. The study investigated heavy metal contamination of water, soils and crops at two peri urban areas in Zambia. Two study sites were New Farm Extension in Mufulira Town in the Copperbelt Province and Chilumba Gardens in Kafue Town in Lusaka Province. The heavy metals investigated were lead, copper, cobalt, nickel and chromium. These heavy metals were found to be higher than acceptable limits in wastewater used to irrigate crops and there are potential human health risks associated with consumption of heavy metal contaminated food crops which have implications on the livelihoods of people. Samples of water, soil and crops were collected and analysed for lead (Pb), copper (Cu), chromium (Cr), cobalt (Co) and nickel (Ni) using the Atomic Absorption Spectrometer (AAS). The data on heavy metals was analysed using mean, standard error and T-test. The results indicated that the levels of heavy metals in wastewater, soil and food crops were above acceptable limits at two study sites. It can be concluded that there was heavy metal contamination of wastewater, soil and food crops at the two peri-urban areas in Zambia. The study highlighted the actual levels of heavy metal contaminant uptake in food crops consumed by the peri urban population. The information from this study can be used by the relevant authorities to develop appropriate measures for monitoring and control of heavy metal contamination in wastewater irrigation farming systems in peri urban areas inZambia.
文摘Ability to modify plants at the genomic level by advanced molecular technology has enhanced the scope of improvements in plant traits attempted earlier through conventional breeding methods. Techniques such as genetic transformation have opened new vistas whereby functional genes, not commonly present in a particular species can be added from other species. The traits incorporated into the genetically engineered plants in the beginning were confined to those governed by dominant genes, e.g. insecticide resistance and herbicide tolerance but advancements with time now also permit the transfer of complexly inherited traits such as drought and cold tolerance. Transgenic technology is also useful in understanding gene expression and metabolic pathways which can then be used to harness the full genomic potential of the plant. This review presents a narrative on development of transgenics and their use for the improvement of field, industrial and pharmaceuticals crops. In addition, discussions are made on current status on genetically modified crops, hurdles to genetic engineering, overcoming strategies and future scope.
文摘S?o Paulo State is the main sugar cane producer and these agricultural activities are carried out in predominantly sandy soils, which require large amounts of phosphate fertilizers and amendments. This work evaluated the fertilizer-effect on the Al, Ba, Fe, Mn and Ni released in a watershed with influence of sugar cane crops in the S?o Paulo State, Brazil, namely the Monjolo Grande Stream basin. Five surface water sampling campaigns were carried out at the mouth of Monjolo Grande Stream in February, April, June, September and November 2010, characterizing the following parameters: discharge, pH, temperature, electric conductivity, dissolved oxygen and total and dissolved concentrations of Al, Ba, Fe, Mn and Ni. Approximately 99% of Al and Fe are transported annually in association with suspended sediments carried to the Monjolo Grande Stream by sheet erosion. The results also demonstrated that the increasing Al, Ba, Fe and Mn concentrations dissolved in the waters of the Monjolo Grande Stream basin in the wet season are associated to phosphate fertilizers and amendments that are used extensively in agrichemical activities. However, with the current application rates, there has been no increase in the dissolved concentrations of these metals at levels that could pose risks to human health.
基金supported by the National Key Research and Development Program of China(2022YFD1901500/2022YFD1901505)the Key Laboratory of Molecular Breeding for Grain and Oil Crops in Guizhou Province,China(Qiankehezhongyindi(2023)008)the Key Laboratory of Functional Agriculture of Guizhou Provincial Higher Education Institutions,China(Qianjiaoji(2023)007)。
文摘Monitoring agricultural drought using remote sensing data is crucial for precision irrigation in modern agriculture.Utilizing unmanned aerial vehicle(UAV)remote sensing,we explored the applicability of an empirical crop water stress index(CWSI)based on canopy temperature and three-dimensional drought indices(TDDI)constructed from surface temperature(T_(s)),air temperature(T_(a))and five vegetation indices(VIs)for monitoring the moisture status of dryland crops.Three machine learning algorithms(random forest regression(RFR),support vector regression,and partial least squares regression)were used to compare the performance of the drought indices for vegetation moisture content(VMC)estimation in sorghum and maize.The main results of the study were as follows:(1)Comparative analysis of the drought indices revealed that T_(s)-T_(a)-normalized difference vegetation index(TDDIn)and T_(s)-T_(a)-enhanced vegetation index(TDDIe)were more strongly correlated with VMC compared with the other indices.The indices exhibited varying sensitivities to VMC under different irrigation regimes;the strongest correlation observed was for the TDDIe index with maize under the fully irrigated treatment(r=-0.93).(2)Regarding spatial and temporal characteristics,the TDDIn,TDDIe and CWSI indices showed minimal differences Over the experimental period,with coefficients of variation were 0.25,0.18 and 0.24,respectively.All three indices were capable of effectively characterizing the moisture distribution in dryland maize and sorghum crops,but the TDDI indices more accurately monitored the spatial distribution of crop moisture after a rainfall or irrigation event.(3)For prediction of the moisture content of single crops,RFR models based on TDDIn and TDDIe estimated VMC most accurately(R^(2)>0.7),and the TDDIn-based model predicted VMC with the highest accuracy when considering multiple-crop samples,with R^(2)and RMSE of 0.62 and 14.26%,respectively.Thus,TDDI proved more effective than the CWSI in estimating crop water content.
基金supported by the Scientific and Innovative Action Plan of Shanghai(21N31900800)Shanghai Rising-Star Program(23QB1403500)+4 种基金the Shanghai Sailing Program(20YF1443000)Shanghai Science and Technology Commission,the Belt and Road Project(20310750500)Talent Project of SAAS(2023-2025)Runup Plan of SAAS(ZP22211)the SAAS Program for Excellent Research Team(2022(B-16))。
文摘Traditional transgenic detection methods require high test conditions and struggle to be both sensitive and efficient.In this study,a one-tube dual recombinase polymerase amplification(RPA)reaction system for CP4-EPSPS and Cry1Ab/Ac was proposed and combined with a lateral flow immunochromatographic assay,named“Dual-RPA-LFD”,to visualize the dual detection of genetically modified(GM)crops.In which,the herbicide tolerance gene CP4-EPSPS and the insect resistance gene Cry1Ab/Ac were selected as targets taking into account the current status of the most widespread application of insect resistance and herbicide tolerance traits and their stacked traits.Gradient diluted plasmids,transgenic standards,and actual samples were used as templates to conduct sensitivity,specificity,and practicality assays,respectively.The constructed method achieved the visual detection of plasmid at levels as low as 100 copies,demonstrating its high sensitivity.In addition,good applicability to transgenic samples was observed,with no cross-interference between two test lines and no influence from other genes.In conclusion,this strategy achieved the expected purpose of simultaneous detection of the two popular targets in GM crops within 20 min at 37°C in a rapid,equipmentfree field manner,providing a new alternative for rapid screening for transgenic assays in the field.
文摘Hail is one of meteorological disasters affecting crop growth in Ulanqab City.It happens frequently from May to September,and this period is also the main growing season of crops.In this period,hail will cause damage to crops,make farmland soil harden,and bring varying degrees of harm to agricultural production.Artificial hail suppression is an important scientific and technological means for disaster prevention and mitigation.It is necessary to strengthen the monitoring,analysis and forecast of severe convection weather,intensify the release of early warning information of hail weather,provide accurate and reliable real-time information for the implementation of artificial hail suppression operations,strengthen the implementation of artificial weather modification,effectively carry out artificial hail suppression operations,and avoid and reduce the impact of hail disaster.
文摘Rising atmospheric CO2 levels pose many challenges to global climate, thus to all forms of life including plants. The impact of elevated CO2 on plant growth and development and the nutritional quality in relation to major nutrients in many crops has been explored extensively. However, information on the elevated CO2 effects on the health-promoting phytochemicals in food crops is rather limited. Major nutrients in food crops including protein, phosphorus, potassium, calcium, iron, zinc and other micronutrients in many food crops are known to be suppressed at elevated CO2 levels. Elevated CO2 increases carbohydrate accumulation but decreases nitrogen accumulation in plants thus affecting their C-N ratio. A number of studies show that high C-N ratio and nitrogen limiting conditions in plants can result in the accumulation of carbon-based secondary metabolites, many of which are health-promoting phytochemicals and allelochemicals involved in plants’ defense against pathogens and herbivory. Although the results from these studies are variable, it can be concluded that while elevated CO2 is known to suppress the content of major nutrients, it may actually have a favorable impact on the accumulation of carbon-based phytochemicals in food crops.
文摘Typical row-crop agricultural practices can potentially be harmful to soil health and future sustainability. The use of cover crops (CC) as a mechanism to improve soil health on a wide scale remains underutilized. Soil health remains a major concern for the sustainability of agricultural productivity, therefore, research into CC implementation as a mean to preserve or improve soil health is warranted. The objective of this study was to evaluate the effects of CC on the soils in the eastern Arkansas portion of the Lower Mississippi River Valley (LMRV) over time for various chemical soil parameters, including pH, soil organic matter (SOM), soil elemental contents (i.e., P, K, Ca, Mg, S, Na, Fe, Mn, Zn, Cu, and B), soil respiration, and a generalized soil health score index. Soil pH decreased over time under both CC and no-cover-crop (NCC) treatments, by −0.3 and −0.2, respectively. Soil OM decreased over time under NCC by −0.1%, but did not differ between CC treatments. Soil N availability decreased over time under NCC (−22.6 kg·ha−1), but did not change over time under CC. Soil respiration decreased over time under both CC and NCC, by −76.1 mg·L−1 and −77.3 mg·L−1, respectively, though there was no effect of CC treatment. The Haney soil health score index decreased under CC (−7.0) and NCC (−6.8) without an effect from CC treatment. Results of the study place emphasis on the temporal nature of soil health as influenced by cover crops and their potential to improve soil health.
文摘It is ordinarily common for forage production in southern Kyushu to adopt a double cropping system, composed of summer forage crops (e.g. maize and sorghum) cultivated from late March to early September, and winter grass crops (e.g. Italian ryegrass (IR) and oat) from mid-October to the following May. However, if high total digestible nutrient (TDN) production is aimed to introduce winter cereal crops (e.g. wheat and barley) as a replacement of IR, it is necessary to cultivate tropical grass, which has a rapid-growth potential with high crude protein (CP) concentration in a switching period between summer and winter crops. In this study, teff (Eragrostis tef) was tried to evaluate as a candidate crop in the switching period. Yield and quality of two types of triple forage cropping system were determined under maize-teff-barley and maize-teff-wheat in the first and second year, respectively. Compared with the normal year, summer temperature was higher and summer and winter precipitations were lower in the first year, while no climatic disorder was observed in the second year. Even though dry matter yield of teff was minimal in the present system due to weed damage, CP concentration was the highest among crops and TDN yields of the present cropping system tended to be higher in the second year with no drought stress than in the conventional maize-IR system in the region.
文摘This research presented a mathematical model to calculate the consumption of diesel oil and the respective emissions of CO2from 41 agricultural crops (38 permanent and 3 temporary) in Brazil. It contains data obtained between 2000 and 2012, from accreditedbibliographic sources. In addition to spreadsheets containing diesel consumption, resulting from the analysis of the productive processes,this research presents data on energy conversion and forest development used to subsidize CO2 emissions and mitigation options.Specifically for C sequestration of the atmosphere, four options of forest projects were systematized: (1) reforestation with fast growingspecies; (2) forest protection projects, with enrichment plantations; (3) implementation of agroforestry systems (1 st cycle); and (4) urbanafforestation projects (streets and parks). Such alternatives are in line with the proposals of the "sectorial plan for mitigation andadaptation to climate change for the consolidation of a low C emission in agriculture", of the Brazilian Agricultural ResearchCorporation (EMBRAPA). The results show that three temporary products (soybean, sugarcane and cotton) are responsible, for at least,85% of all CO2 emissions, comparatively the low consumption of diesel oil verified in the management of the 38 permanent productsstudied in this research. Therefore, in order to contribute to the reduction of the release of CO2 into the atmosphere, perennial crops andecologically rational extractivism should be more encouraged and more supported by the public authorities.
文摘Genetically Modified Crops (GMCs) and Climate Change (CC) are the two most contentious ecological issues the world faces today. Application of transgenics in agriculture is most debated because of its direct and indirect implications. The advertized benefits in the backdrop of the potentially harmful effects on health and environment make this an issue of greater concern. On the other hand, Climate Change is a problem of enormous scale and its after-effects even more grave. The impact of climate change on agriculture, though well researched, is still very uncertain. Further, the introduction and global embrace of a technology with unverified credentials may prove to be an ill-conceived and ill-timed act. The future of GMC technology in India will be both challenging as well as exciting. Therefore any decision on this front should be taken with scientific rigor and logic. Our aim is to explore this complex inter-relationship and provide impetus for further research.
文摘Nitrate (NO3) leaching is a major issue in sandy soils intensively cropped to potato. Modelling could test the effect of management practices on nitrate leaching, particularly with regard to optimal N application rates. The NO3 concentration in the soil solution is well known for its local heterogeneity and hence represents a major challenge for modeling. The objective of this 2-year-study was to evaluate machine learning regression methods to simulate seasonal NO3 concentration dynamics in suction lysimeters in potato plots receiving different N application rates. Four machine learning function approximation methods were compared: multiple linear regressions, multivariate adaptive regression splines, multiple-layer perceptrons, and least squares support vector machines. Input candidates were chosen for known relationships with NO3 concentration. The best regression model was obtained with a 6-inputs least squares support vector machine combining cumulative rainfall, cumulative temperature, day of the year, N fertilisation rate, soil texture, and depth.
基金the National Council for Scientific and Technological Development (CNPq)Foundation for Research Support of the State of Goiás for their support
文摘Cover crops can provide changes in soil chemical and physical properties, which could allow a sustainable development of soybean and upland rice rotation in Brazilian Cerrado. The objective of this study was to determine the effects of cover crops(cultivated in the offseason) in the soybean-upland rice rotation(cultivated in the summer season) on the soil chemical and physical properties, yield components and grain yield of the cash crops. The experimental design was a randomized block design in factorial scheme 4 × 2 with six replications. Treatments were composed by four cover crops: fallow, millet(Pennisetum glaucum) + Crotalaria ochroleuca, millet + pigeon pea(Cajanus cajans), and millet + pigeon pea + Urochola ruziziensis in the offseason with one or two cycles of cover crops, with rice(Oryza sativa)or soybean(Glycine max) in the summer season. Cover crops alone provided no changes in soil chemical properties. However, the rotation cover crops/cash crops/cover crops/cash crops reduced p H, Al and H + Al and increased Ca, Mg, K and Fe contents in the soil. The cover crops millet + pigeon pea and millet + pigeon pea + U. ruziziensis improved soil physical properties in relation to fallow,especially in the 0–0.10 m soil layer. In spite of the improvement of the soil physical properties after two years of rotation with cover crops and cash crops, the soil physical quality was still below the recommended level, showing values of macroporosity, S index and soil aeration capacity lower than 0.10 m3/m3, 0.035 and 0.34, respectively. Upland rice production was higher under mixtures of cover crops than under fallow, mainly because of soil physical changes done by these mixtures of cover crops.Soybean grain yield was similar under all cover crops tested, but was higher after the rotation cover crops/upland rice/cover crops than after only one cycle of cover crops.
文摘Cover crops are the plants which are grown to improve soil fertility, prevent soil erosion, enrichment and protection of soil, and enhance nutrient and water availability, and quality of soil. Cover crops provide several benefits to soils used for agriculture production. Cover crops are helpful in increasing and sustaining microbial biodiversity in soils. We summarized the effect of several cover crops in soil properties such as soil moisture content, soil microbial activities, soil carbon sequestration, nitrate leaching, soil water, and soil health. Selection of cover crops usually depends on the primary benefits which are provided by cover crops. Other factors may also include weather conditions, time of sowing, either legume or non-legume and timing and method of killing of a cover crop. In recent times, cover crops are also used for mitigating climate change, suppressing weeds in crops and increasing exchangeable nutrients such as Mg2+ and K+. Cover crops are also found to be economical in long-term experiment studies. Although some limitations always come with several benefits. Cover crops have some problems including the method of killing, host for pathogens, regeneration, and not immediate benefits of using them. Despite the few limitations, cover crops improve the overall health of the soil and provide a sustainable environment for the main crops.
文摘Production of energy crops is perceived as a potential source of alternative energy for petroleum oil. However, it is cru-cial to ensure that there is adequate land and water available for production of energy crops before indulging into the business of producing such crops. This paper assesses the availability of land and water resources for production of energy crops in the SADC region using landuse/landcover data, hydrological and meteorological data, as well as socioeconomic data. It is found that Botswana and Mozambique have large amounts of bushland that can be used for expansion of agricultural land including production of energy crops. Zimbabwe has the highest amount of land under cultivation, which makes it difficult for the country to expand its agricultural land. However, land reform processes taking place in Zimbabwe provides a good opportunity to diversify agricultural production including reallocation of farms for production of energy crops. Mozambique has favorable rainfall for production of maize and sugarcane, whereas Zimbabwe can explore growing Jatropha on degraded land and use irrigation for cultivation of sugarcane. High frequency of crop failure in Botswana makes it difficult to grow maize or sugarcane as energy crop. The country can promote production of sweet sorghum, which is traditionally grown by small scale farmers, and explore production of Jatropha in degraded and desert land. A regional approach to address land and water requirements for production of energy crops is considered important as compared to planning for production in each country as the constraints and potential of each country can be fully recognized. More detailed country specific research is needed on the production of the specified energy crops to ensure sustainability of the production systems.
文摘The long-term success of hydrogenase uptake negative legume-rhizobia associations, in spite of their apparent inefficiency, may be explained by the positive effects of H2 release to soil. A primary benefit of H2 release to soil is the stimulation of H2-oxidizing, plant growth promoting rhizobacteria (PGPR) [1]. Two such previously isolated strains were tested as seed inoculants for barley and spring wheat;there were significant differences between treatments and controls in tiller and grain head production, supported by data from greenhouse trials. T-RFLP analysis of barley soil samples, supported by DNA sequencing data, successfully distinguished both species inoculated. Successful re-isolation indicates that these isolates can reproduce themselves in soils and can be used as effective inoculants with peat as the standard carrier. This study showed that we are able to achieve some of the beneficial effects of crop rotation without the need to implement actual crop rotation.
基金financially supported by the National Key Technology Research and Development Program of China(2021YFD1901001-08)the Key Scientific and Technological Project of Henan Provincial Education Department,China(232102111119)。
文摘Nitrogen(N)is a key factor in the positive response of cereal crops that follow leguminous crops when compared to gramineous crops in rotations,with the nonrecyclable rhizosphere-derived N playing an important role.However,quantitative assessments of differences in the N derived from rhizodeposition(NdfR)between legumes and gramineous crops are lacking,and comparative studies on their contributions to the subsequent cereals are scarce.In this study,we conducted a meta-analysis of NdfR from leguminous and gramineous crops based on 34 observations published worldwide.In addition,pot experiments were conducted to study the differences in the NdfR amounts,distributions and subsequent effects of two major wheat(Triticum aestivum L.)-preceding crops,corn(Zea mays L.)and soybean(Glycine max L.),by the cotton wick-labelling method in the main wheat-producing areas of China.The meta-analysis results showed that the NdfR of legumes was significantly greater by 138.93%compared to gramineous crops.In our pot experiment,the NdfR values from corn and soybean were 502.32 and 944.12 mg/pot,respectively,and soybean was also significantly higher than corn,accounting for 76.91 and 84.15%of the total belowground nitrogen of the plants,respectively.Moreover,in different soil particle sizes,NdfR was mainly enriched in the large macro-aggregates(>2 mm),followed by the small macro-aggregates(2–0.25 mm).The amount and proportion of NdfR in the macro-aggregates(>0.25 mm)of soybean were 3.48 and 1.66 times higher than those of corn,respectively,indicating the high utilization potential of soybean NdfR.Regarding the N accumulation of subsequent wheat,the contribution of soybean NdfR to wheat was approximately 3 times that of corn,accounting for 8.37 and 4.04%of the total N uptake of wheat,respectively.In conclusion,soybean NdfR is superior to corn in terms of the quantity and distribution ratio of soil macro-aggregates.In future field production,legume NdfR should be included in the nitrogen pool that can be absorbed and utilized by subsequent crops,and the role and potential of leguminous plants as nitrogen source providers in crop rotation systems should be fully utilized.