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1.
《Field Crops Research》2006,99(1):35-47
Both intensification and diversification of cropping systems may allow improving the productivity and sustainability of agricultural production in the Indo-Gangetic Plain (IGP), but the choices to be made require integrated assessment of various cropping systems. A field experiment was conducted from 1999 to 2002 on a sandy clay loam (Inceptisol) to evaluate nine predominant cropping systems in West Bengal, India. Productivity, energy use efficiency, and nutrient uptake generally increased with increasing cropping intensity. Positive residual effects of potato and jute on yield and energy output of subsequently grown crops were observed as well as maintenance or improvement of soil properties such as soil organic matter, available P, and available K. The P balance was positive for most systems, except for jute-containing systems. However, negative K balances occurred due to almost complete removal of crop biomass in all systems, suggesting that recommended rates of applied K fertilizer were to low for sustaining soil K supply over the longer term. Cropping systems containing potato had the highest levels of yield, net return, benefit to cost ratio and energy productivity, but energy use efficiency was reduced due to higher energy consumption in these systems. Jute–wheat and jute–rapeseed–rice systems showed high energy use efficiency along with moderate cost and return. Based on economic considerations alone, jute–potato–rice, rice–potato–rice and rice–potato–sesame can be recommended as cropping systems for resource-rich growers in the eastern part of the IGP. Systems such as jute–wheat, rice–wheat and jute–rapeseed–rice appear to be most suitable for small and marginal farmers that cannot afford the large production costs associated with crops such as potato.  相似文献   

2.
The soil as a resouce in potato production must be maintained if potato production is to be sustained into the 21st century. Increased pest resistance, resource scarcity, and increased input costs will all be important in determining the availability of technology in the future. As demands to maintain and improve environmental quality increase, our ability to overcome poor soil management by increased inputs may be restricted. j To sustain soil as a resource more attention must be given to soil organic matter, structure, and water holding capacity. Cropping systems that increase crop residue returned to the soil and reduce tillage can increase soil organic matter levels and improve soil physical properties. Greenmanure crops may also help reduce pathogen populations. Soil compaction, soil erosion, and salinization represent the most significant threats to maintaining the soil resource. Compaction can significantly limit the soil’s ability to supply water and nutrients to the plant by limiting water holding capacity and root growth. Limiting rooting depth increases the potential for nitrates to be leached below the rooting zone. Erosion, through the removal of the most productive topsoil, has the potential to destroy soil productivity. The actual impact of erosion over time is very difficult to measure and has been compensated for by increased inputs. Salinization throughout history has decreased productivity of irrigated soils. The sustainability of the soil resource depends upon the development and use of Best Management Practices that maintain or improve soil physical properties, while minimizing soil compaction and erosion. These practices will have to be developed within the parameters established by changing human needs and expectations.  相似文献   

3.
Low-input and organic farming systems have notable differences in nitrogen (N) sources, cycling and management strategies compared to conventional systems with high inputs of synthetic N fertilizer. In low-input and organic systems, there is greater reliance on complex rotations including annual and perennial crops, organic N sources, and internal N cycling that more closely mimic natural systems. These differences in farming system practices fundamentally affect N availability and N use efficiency (NUE) and could impact crop traits and breeding strategies required to optimize NUE. We assess genetic and environmental factors that could assist breeders in improving crop performance in low-input and organic farming systems by examining NUE in natural and agricultural ecosystems. Crop plants have often been bred for high N productivity, while plants adapted to low N ecosystems often have lower productivity and higher levels of internal N conservation. Breeders can potentially combine N productivity and N conservation through the use of elite and wild germplasm. Beneficial genetic traits include the ability to maintain photosynthesis and N uptake under N stress and the ability to extract soil N at low concentrations, perhaps through beneficial associations with soil microorganisms. In addition, breeding for specific adaptation to climactic and management practices so that crop uptake patterns match N availability patterns, while minimizing pathways of N loss, will be critical to improving NUE.  相似文献   

4.
Microbial communities in soils provide numerous functions vital to agricultural productivity, and there is growing interest in understanding and manipulating these communities to achieve more sustainable production systems. We investigated microbial communities in potato fields in Wisconsin to determine the extent to which microbial communities were structured by inherent soil properties versus factors under grower control. We found that soil properties, including texture and chemistry, shaped microbial communities at broad levels, determining the diversity and abundance of phyla. Organic versus conventional management, however, correlated with finer scale differences in microbial communities, while crop variety was not associated with microbial community composition in this study. These results suggest that grower practices have the potential to alter microbial communities, but these effects will take place within an existing soil context. Future research is necessary to determine how these patterns in microbial community structure relate to functional outcomes for plant health.  相似文献   

5.
Precision agriculture is a farming management concept based on observing, measuring and responding to inter- and intra-field variability in crops. In this paper, we focus on responding to intra-field variability in potato crops and analyse variable rate applications (VRAs). We made an overview of potential VRAs in potato crop management in The Netherlands. We identified 13 potential VRAs in potato, ranging from soil tillage to planting to crop care to selective harvest. We ranked them on availability of ‘proof of concept’ and on-farm test results. For five VRAs, we found test results allowing to make a cost-benefit assessment. These five VRAs were as follows: planting, soil herbicide weed control, N side dress, late blight control and haulm killing. They use one of two types of spatial data: soil maps or biomass index maps. Data on costs and savings of the VRAs showed that the investments in VRAs will pay off under practical conditions in The Netherlands. Savings on pesticide use and N-fertilizer use with the VRAs were on average about 25%, which benefits the environment too. We foresee a slow but gradual adoption of VRAs in potato production. More VRAs will become available given ongoing R&D. The perspectives of VRAs in potatoes are discussed.  相似文献   

6.
Summary

Cultivars can be selected for traits that improve water use efficiency, and fertilizers and other nutrient sources also can be managed to optimize water use efficiency of a crop. Both cultivar selection and nutrient management impact water use efficiency by altering photosynthetic rate, yield, rooting characteristics, transpiration, or soil evaporation. In order to optimize water use efficiency, cultivar and nutrient decisions should be made jointly. This integrated approach will lead to improvements in water use efficiency, with an increase in productivity and profitability per unit water.  相似文献   

7.
Sustainable management of phosphorus (P) is a critical component of potato production systems because of a comparatively high plant P requirement, soil reactions that create management challenges, and potential environmental degradation from inappropriate P management. Phosphorus affects potato plant growth in many ways including its effects on plant metabolism, cellular structural components, canopy development, tuber set, nutritional quality, and resistance to some diseases.  相似文献   

8.
Phosphorus (P) losses from agricultural systems are a cause of degraded surface water quality of lakes and streams. In freshwater systems, P is often the most limiting nutrient for algae growth and an increase in P additions to these systems can cause a shift in ecology. These shifts can result in a degradation of the water resource as habitat or for recreation. In an effort to combat the negative effects of agriculture management practices on surface water quality, federal and state regulations require some level of assessment to guide P applications. Areas with large amounts of potato production are of particular concern with respect to P loss since potatoes are a high P demanding crop and are inefficient users of applied P. In many cases, soils in potato production are managed with a higher soil test P concentration compared to other crops and P applications for optimum production exceed P removal. When potato production fields are maintained at high soil test P levels, this may increase the risk of P loss in runoff. However, based on soils and landscape positions where potatoes are grown, there may be little risk of transport. While there appears to be little risk of P loss on low-sloping, sandy soils, output from the Wisconsin Phosphorus Index suggests that more steeply sloping fields can pose some risk, especially when soil test P concentrations exist at above optimum levels. At high soil test P levels, no P may be required for optimum yield in rotated crops, but production practices of these crops may need to be altered to reduce P losses. Furrow-irrigated and tile-drained fields may also pose risks of P loss to the environment. While the P demands of potato are greater than those for most crops, it is likely that most of this P will not be exported via surface runoff. Careful management considerations must be made when producing potatoes on high sloping soils, especially those close to surface water bodies. Future considerations of P management and water quality will focus on assessing leaching risk of P and this contribution to surface waters.  相似文献   

9.
Improving nitrogen use efficiency is important for the potato crop, because of its relatively low ability to take up available soil mineral nitrogen (N). Splitting of N fertilizer application is a suitable approach to better match N need and supply. In-season crop N monitoring methods are therefore required to support such strategies. This paper deals with the state of the art and potential development of characteristics, use and implementation of well known and more recent methods aimed to assess in-season potato Crop Nitrogen Status (CNS). A short overview of this concept is given for the potato crop. The most important and available methods for CNS assessment are evaluated for their accuracy, precision, sensitivity, sensibility and feasibility. These are: the petiole sap nitrate concentration test; the leaf chlorophyll concentration measurement using a hand-held chlorophyll meter; the measurement of crop light reflectance through a hand-held radiometer using passive sensors. More recent methods still under investigation based on near, ground-based, air-borne or space-borne remote sensing are discussed for their scientific and practical interest in the near future. The current and potential use and implementation of these methods into decision support systems for potato N fertilization management aimed at improving the potato crop nitrogen use efficiency are analysed by: comparing relative and raw data; establishing threshold values of CNS; and combining or integrating the CNS values into models dedicated to N recommendation or to crop growth simulation.  相似文献   

10.
Environmental impacts of potato nutrient management   总被引：1，自引：0，他引：1  
Use of soluble chemical fertilizers for crop production, particularly to supply nitrogen, phosphorus, and potassium, has increased potato yields and quality for several decades. Over the past 10 years, however, there has been an increased concern over the environmental impact of agricultural fertilizers, particularly as nonpoint sources of water pollution. Currently, nitrogen is a target for improved use efficiencies in potato to reduce potential nitrate contamination of groundwater. Phosphorus management is increasingly being examined as a potential non-point source contaminant of surface waters. Potato researchers throughout North America are conducting studies that focus on maintaining or enhancing crop production while reducing the potential of negative environmental impacts. Precision agriculture, cover crops, slow-release fertilizers, and genetic manipulation are key strategies being studied. Concurrently, new challenges are arising, such as concerns over phosphorus leaching and heavy metal contamination in fertilizers. These have the potential to restrict nutrient use in agricultural systems, requiring both potato producers and scientists to seek additional alternatives to improve nutrient-use efficiency.  相似文献   

11.
A primary objective of phosphorus (P) management is to maintain optimal levels of P in the soil solution at the root surface. Potato plants typically have low root density, resulting in higher solution P concentration needs and critical soil test levels than most other common crop plants. The chemistry of P in fertilized soils makes maintaining these high P concentrations a challenge. Phosphorus has a very high affinity for the soil solid phase with iron (Fe) and aluminum (Al) dominating reactions in moderately acid soils and calcium (Ca) in alkaline soils. Guidelines for P stewardship for potato production are: (1) adopt practices that develop soil conditions that favor root growth and development; (2) make source, rate, time and placement decisions for nutrient applications that maintain optimal soil solution P concentrations during critical growth stages; and (3) use soil and water conservation practices to minimize P losses from the root zone and the field.  相似文献   

12.
Effects of pest and soil management systems on potato diseases   总被引：1，自引：0，他引：1  
Long-term cropping systems research is important in order to reduce production costs, to control crop pests, and to optimize the sustainability of agro-ecosystems. Soil amendment use, improved disease management practices, and careful cultivar choice are some of the potential components for improving potato production systems. This research was conducted in long-term cropping systems plots in order to evaluate the impact of soil amendments, pest management practices, and cultivar on foliar and soil-borne potato diseases and to assess the relationships of soil and pest management practices to disease levels and soil microbial activity. Fungicide applications for management of foliar diseases varied between the pest management systems (e.g., biological, reduced input, and conventional). Incidence of potato foliar diseases was quantified five times during the cropping season. The impact of soil amendment and pest management practices on soil microbial activity and tuber-borne diseases was also investigated. Low incidences of foliar and selected soil-borne diseases were recorded. Disease levels varied between years, cultivars, pest management, and soil amendments. Significant differences between cultivars were detected for early blight, white mold, and black dot. The cultivar Superior had higher incidence of white mold and black dot, while cv Atlantic had higher early blight incidence. Pest management system significantly affected foliar early blight incidence in 1998, but not in 1997. Pest management system did not affect late blight, white mold, or black dot incidence, or tuber disease incidence in either year. The addition of soil amendments significantly impacted tuber black dot incidences. Microbial activity responded to increasing temperature as the season progressed and was significantly enhanced by the addition of manure and compost soil amendments; however, lower disease incidence was not associated with increased microbial activity. While pest management practices were not major determinants of disease levels in these experiments, the results show that soil amendments can increase incidence of selected tuber diseases and microbial activity in soils.  相似文献   

13.
Summary

Nutrient-efficient crops have an important role in modern agriculture. In the low-input systems that characterize most of world agriculture, nutrient-efficient crops improve crop productivity. In high-input systems of the developed world, nutrient-efficient crops are valuable in reducing pollution of surface and ground water resources from intense fertilization. Recent developments in molecular biology, root biology, rhizosphere interactions, and modeling present new opportunities for the understanding and improvement of crop nutrient efficiency. The degree and extent of nutritional limitations to crop productivity, and the economic and ecological liabilities of intensive fertilization, are such that eventually nutrient-efficient crops will be an important part of integrated nutrient management of cropping systems.  相似文献   

14.
Dan O. Chellemi 《Crop Protection》2000,19(8-10):855-858
Adaptation and acceptance of pest control in low-input agriculture will be largely influenced by the approach used to manage soil-borne pests. A single tactic approach, consisting of the routine application of a broad spectrum biocide or biocides to disinfest soil is not compatible with the goal of minimizing inputs and will not have wide-scale applicability in low-input production systems. An integrated pest management (IPM) approach can be compatible with low-input systems but is often difficult to implement due to inherent constraints associated with identifying and treating organisms in the soil. Additionally, IPM will require more intensive knowledge of biological interactions in the soil and the timely management of that information, which may not be practical in low input systems. A pro-active approach, in which the production system is designed to avoid the outbreak of pests, minimizes the use of inputs in crop production by reducing the need for intervention treatments. Traditionally, the impact of soil-borne pests is not considered until after the production system has been designed and implemented. Combining biologically based pest control methods with a production system designed to minimize their impacts offers the most sustainable approach for low-input agriculture.  相似文献   

15.
Abstract

Understanding the major limitations to root growth is very important if we are to maximize water and nutrient use and increase yields. Limitations may be insufficient rooting depth, root diseases, nutrient deficiencies, toxicities and soil hardness. An understanding of these limitations will lead to more precisely identifying traits for which to select and breed. Examples of successfully overcoming limiting factors to improve crop performance by breeding and selection are given for cereal cyst nematodes in wheat, soil acidity and salinity. The importance of altered crop management practices to reduce limitations is also stressed. These have resulted in a more effective and healthier root system, which results in more water use and greater yields. Opportunities to genetically increase the size of the root system in dryland systems where water and nutrients are not all used by the crop are given.  相似文献   

16.
Increased productivity of potatoes can improve the livelihood of smallholder potato farmers in Kenya, Uganda and Ethiopia and is required to meet the growing demand. This paper investigates the opportunities for potato system improvement that could result in improved productivity. Through a diagnosis of the potato systems in the three countries on the basis of surveys and stakeholder workshops, seed potato quality management, bacterial wilt control, late blight control and soil fertility management were identified as key technical intervention topics. For effective problem solving in these areas, the functioning of the potato innovation system requires improvement to better deliver the functions of potato marketing as well as knowledge development and information exchange. With use of a ‘system failure framework’ the shortcomings of the potato innovation system are identified and discussed and options for improvement are suggested.  相似文献   

17.
An experiment was conducted in three fallow paddy fields situated on the mid-tropical plain zone of a northeastern Indian state(Tripura) to provide rice fallow management options using leftover soil moisture and nutrients. The three experimental fields were managed by growing rice under the system of rice intensification as the rainy season crop and then groundnut, lentil, rapeseed and potato as the post-rainy season crops. Fertilization under the integrated nutrient management system and lifesaving irrigation at critical stages of each post-rainy season crop were provided. Results showed that the field water use efficiency values were 5.93, 2.39, 2.37 and 59.76 kg/(hm2·mm) and that the yield of these crops increased by approximately 20%, 34%, 40% and 20% after applying two lifesaving irrigations in groundnut, lentil, rapeseed and potato, respectively. Therefore, fallow paddy field can provide possible profitable crops during the post-rainy season by utilizing the residual moisture and minimum supplemental irrigation under improved nutrient management practices.  相似文献   

18.
Plant nutrients are important components of the intensive production system used for potatoes. Nutrient management practices need to be improved for sustained and increased productivity. Better mangement decisions will be made when accurate information is available about (a) crop residues and rotation effects on nutrient cycling, (b) the nutritional characteristics and requirements of each variety, (c) bioavailability of nutrients in soils, and (d) fertilization and tillage effects on nutrient-use efficiencies. Plant growth and nutrient uptake responses to different nutrient availabilities must also be understood to maximize growth and nutrient efficiencies. Diagnostic management techniques for nutrients need to be related to fundamental chemical and biological processes in the soil and plant system to be applicable to different environments. This information can then be packaged with other knowledge into a comprehensive crop management system. These changes should bring our agronomic practices into better harmony with the natural processes of the production system, and yet be responsive to social and environmental concerns, and economic reality.  相似文献   

19.
SUMMARY

Cropping system refers to temporal and spatial arrangements of crops, and management of soil, water and vegetation in order to optimize the biomass/agronomic production per unit area, per unit time and per unit input. Soil quality refers to its intrinsic attributes that govern biomass productivity and environment moderating capacity. It is the ability of soil to perform specific functions of interest to humans. Three components of soil quality (e.g., physical, chemical and biological) are determined by inherent soil characteristics, some of which can be altered by management. Soil quality and soil resilience are inter-related but dissimilar attributes. Resilient soils, which have the ability to restore their quality following a perturbation, have high soil quality and vice versa. Decline in soil quality sets-in-motion degradative processes, which are also of three types, namely physical (e.g., compaction, erosion), chemical (e.g., acidification, salinization) and biological (e.g., depletion of soil organic matter content). Soil degradation, a biophysical process but driven by socioeconomic and political causes, adversely affects biomass productivity and environment quality. Determinants of soil quality are influenced by cropping systems and related components. Dramatic increases in crop yields during the 20th century are attributed to genetic improvements in crops, fertilizer use, and improved cropping systems. Dependence on fertilizers and other input, however, need to be reduced by adopting cropping systems to enhance biological nitrogen fixation and use efficiency of water and nutrients through conservation tillage, cover crops, and improved methods of soil structure and nutrient management.  相似文献   

20.
For organic potato producers the two main challenges are disease and nutrient management. Both factors are limited by regulations that on the one hand prohibit the use of chemical fertilisers, especially nitrogen and, on the other hand, most synthetic pesticides. Late blight, caused by Phytophthora infestans is commonly thought to be the factor most limiting yield. However, because there is no really effective fungicide available to control late blight, there are virtually no yield loss data available for organic farming conditions. In this paper the state of the art of organic potato management with respect to disease and nutrient management is summarised. In a second part, the interactive effects of N-availability in the soil, climatic conditions and late blight were studied in the presence and absence of copper fungicides from 2002–2004 for the mid-early main-crop potato cv. Nicola. From the experimental work it became clear that copper fungicides in most cases do slow down epidemics adding an average of 3 days to the growth duration. However, only 30% of the variation in yield could be attributed to disease reduction. A model including disease reduction, growth duration and temperature sum from planting until 60% disease severity was reached, and soil mineral N contents at 10 days after emergence could explain 75% of the observed variation in yield. However, the model failed when N-supply was extremely high. The implications of the results on the management of organic potatoes with respect to cultivar choice, nutrient and disease management are discussed. In conclusion, several points emerge from the results: In organic farming, yields are foremost limited by nutrient availability in spring and early summer. The effects of late blight on yields may often be overestimated and cannot be deducted from results in conventional farming because of the strong interaction with nutrient status. Resistance clearly remains the most important strategy against late blight in organic potato production. However, as important or even more important than resistance is the early development and bulking behaviour and the ability of a cultivar to make use of organic nutrients efficiently. In the absence of efficient organic pesticides it is possible to reduce blight pressure to a certain extent by arranging the crop in small narrow fields perpendicular to the main wind direction neighboured either by non-hosts or completely resistant potatoes.  相似文献   

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