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1.
《Field Crops Research》2001,70(2):139-151
The effects of various crop rotations on the biomass and yield of barley (Hordeum vulgare L.), faba bean (Vicia faba L.), and pea (Pisum sativum L.) grown under Mediterranean conditions were studied during three growing seasons in the semiarid Spanish Central Plateau. The treatments comprised six crop sequences: barley monoculture, fallow–barley (currently used in the area), faba bean–barley, pea–barley, fallow–barley–faba bean, and fallow–barley–pea. The fallow was of 16-month duration. The site is representative of cultivated areas of the Plateau, and the soil has a loam texture. Results concentrate on barley as the main crop. Season distribution of rainfall restricted the effectiveness of the management practices and in consequence there were few differences between rotations. Barley had greater biomass and yield after fallow than after other crops but significant differences were dependent on year. Legumes, an alternative to fallow, increased land use, permitted alternative weed control measures, and reduced the need for fertiliser. The intensification of the fallow–barley cropping system is best achieved by reducing the frequency of fallow and including other crops of relatively small biomass production, thereby minimising the impact on yield of the succeeding barley crop.  相似文献   

2.
Potato cropping systems in Maine include both continuous potatoes and short-term potato rotations with small grains. Producers recognize the benefits of increased rotations, but the economics of producing a high-valued crop such as potatoes (Solanm tuberosum L.) create incentives for continuous potato production. Research at the USDA-ARS research site in Newport, ME, is evaluating the agronomic and economic impacts of five crops in two-year rotations on potato production and whole-farm profitability. The rotation crops are barley (Hordeum vulgare L.), sweet corn (Zea mays L.) green bean (Phaseolus vulgares L.), soybean (Glycine max L., Mer.), and canola (Brassica napus L.). Enterprise budgets for the five crops were developed. The budgets and historical prices and yields were used as inputs to a Monte Carlo simulation. The simulation was conducted to determine the impact of rotation crops on whole-farm profitability and income risk, as measured by income variability. The net incomes of the five rotation sequences were compared against continuous potatoes. Two rotation crops, sweet corn and green beans, resulted in an increase in net income relative to continuous potatoes. AU of the rotation crops were found to greatly reduce income risk and chance of economic losses. In the case of green beans and sweet corn, the analysis was rerun using data from the research trials on the following potato crop yields. Depending on whether the rotation effect was negative or positive, net income either fell or rose when compared to fist analysis. However, even when the rotation crop led to decreased yields in the following potato crop, income variability and likelihood of economic loss was still superior to the continuous potato rotation. These findings provide support for including rotation crops as a method to improve potato production and sustainability, increase wholefarm profitability, and reduce income risk.  相似文献   

3.
Potato is a major cash crop for Bhutanese highland farmers, who widely use intercropping systems combining potato (Solanum tuberosum) with maize (Zea mays). Scarcity of information on existing cropping practices limits the scope of present extension programs. Experiments evaluating potato intercropping systems with maize and faba bean (Vicia faba) were conducted at Yusipang (2700 m) and Kangma (1900 m). Potato yield reductions through intercropping ranged from 0–21 percent depending on year, and location. Variation in planting geometry and maize planting date did not affect potato yield reductions. The land equivalent ratio ranged from 1.03–1.06 for faba bean and from 1.11 to 1.49 for maize intercropping systems. Compared to potato as a sole crop maize intercropping increased gross benefits in Kangma by 12–15 percent with maize plant densities of 2.8 per m2. In Yusipang, gross benefits were not increased through intercropping. Reducing risks of environmental and market impacts favor the use of intercropping systems.  相似文献   

4.
《Field Crops Research》2005,91(1):91-105
A velvet bean (Mucuna pruriens L.) module for the agricultural production systems simulator (APSIM) was developed in order to assess the nitrogen (N) and yield benefits of velvet bean green manure crops, when grown in rotation with maize in small holder situations in Malawi. The velvet bean module was able to simulate maturity biomass from six contrasting sites in Malawi over an observed range of 847–10,420 kg/ha with a root mean squared deviation (RMSD) of 1562 kg/ha. APSIM was then tested for its ability to simulate the response of maize crops to fertiliser N in two seasons, to previous velvet bean green manure crops in one season, or both in combination in one season. With no previous velvet bean crop, the response to fertiliser N varied across sites from a non-significant increase to an eight-fold increase in maize yield. Where a velvet bean crop was grown in the previous season, the response to applied N varied from non-significant to slight. Simulated yields were within one standard error of the observed in the majority of cases. A sensitivity analysis for key parameters in the velvet bean module highlighted, that those governing the N content of crop root and shoot residues had greatest impact on maize yield response. Parameters controlling production and partitioning of root or shoot biomass were less important.To our knowledge this is the first reported case of a cropping systems simulation model being tested for its ability to simulate the production of a green manure legume followed by a cereal.  相似文献   

5.
Using actual potato production data from Aroostook County, Maine, we investigate the possibility of producers increasing net revenues by modifying rotation practices. By examining rotations as a whole, and incorporating yield effects and changes in production costs across rotations, more realistic pictures of net revenues for each rotation develop than if net revenue for each crop within a rotation is considered independently. Our analyses indicate producers can alter their production practices within the range of rotations used locally to increase net revenues. A key finding confirms the synergistic interaction between grains underseeded with a green manure crop and round-white potato varieties, resulting in decreased production costs, greater potato yields, and increased net revenues.  相似文献   

6.
Cropping systems that integrate cover crops into crop rotations, reduce tillage intensity and frequency, and maintain residue cover have the potential to improve agricultural sustainability in drylands. However, there is much yet to learn about the benefits of cover crops in sustainable dryland farming in the southern Great Plains (SGP). We reviewed the literature on the effects of cover crops on soil organic carbon (SOC), nitrogen, soil water conservation, and crop yields in dryland cropping systems of the US Great Plains (GP), and analyzed the opportunities and challenges for integrating cover crops into dryland crop-fallow systems of the SGP. Majority of the studies in the central Great Plains (CGP) and the northern Great Plains (NGP) of the United States suggest that cover cropping improves sustainability of cropping systems through their positive effects on SOC accumulation, nutrient cycling, soil erosion control, weed suppression, and soil health improvement. However, integrating cover crops into dryland cropping systems of the SGP faces challenges because of low quantity of soil-water availability. More research on the tradeoff between water use and other agroecosystem benefits of cover cropping is required to successfully integrate cover crops into dryland cropping systems in the SGP.  相似文献   

7.
Crop yields are often increased through crop rotation. This study examined selected soil chemical and physical properties that may constitute the N and non-N related effects of crop rotation in potato cropping systems. Potato (Solanum tuberosum L. Norwis) was grown continuously and in two-year rotations with annual alfalfa (Medicago sativa L. Nitro), hairy vetch (Vicia villosa Roth), white lupin (Lupinus albus L. Ultra), and oat (Avena sativa Astro). Hairy vetch contributed more residue N than any other crop rotation, ranging from 110 to 119 kg N ha?1. Inorganic N concentrations in potato soils were related to the previous crop’s residue N contents, and were highest following vetch and alfalfa and lowest following oat and potato. The highest mineralizable N concentration was found following vetch (46.6 mg N kg?1). Saturated soil hydraulic conductivity in potato following all rotations ranged from 9.88 to 11.28 cm h?1 compared to 5.71 cm h?1 for continuous potato. Higher soil water contents were maintained in the 30 to 45 cm depth for all rotations compared to continuous potato. Thus several parameters indicate substantial N effects associated with particular crop rotations. Soil hydraulic conductivity and soil water status may also represent significant components of the rotation effect not directly related to N for these cropping systems.  相似文献   

8.
Intercropping of grain legumes with cereals may offer several advantages over sole crops for forage production and is commonly used, particularly in low‐input agriculture. Faba bean (Vicia faba L.), oat (Avena sativa L.) and triticale (×Triticosecale Wittmack) sole crops as well as the intercrops of faba bean with each of the above cereals, in three seeding ratios (75:25, 50:50 and 25:75), were compared for dry‐matter (DM) yield, nitrogen (N) concentration, chlorophyll content, growth rate and plant height in a 2‐year field experiment. Triticale sole crop and faba bean intercrops with triticale provided higher DM yield than faba bean sole crop and the intercrops of faba bean with oat. Growth rates of faba bean, oat and triticale in mixtures were lower than those in sole crops. Faba bean plants were taller in the intercrops than in the sole crop at 3 weeks after tillering (WAT), whereas at 6 WAT, the trend was different as faba bean plants in the sole crop were taller than in the intercrops. N concentration was higher for the cereals when faba bean was included in the mixture. Crude protein (CP) concentration was the highest in faba bean sole crop followed by the faba bean intercrops with oat. However, triticale sole crop and faba bean mixtures with triticale provided higher CP yield than all other crops because of their highest DM yield. Thus, mixtures of faba beans with triticale could be a promising alternative for increased forage production because of their capacity for high DM and protein yields.  相似文献   

9.
Arthropods are an important group of macroorganisms that work to maintain ecosystem health. Despite the agricultural benefits of chemical control against arthropod pests, insecticides can cause environmental damage. We examined the effects of one and two applications of the insecticides chlorfenapyr (0.18 liters a.i. ha-1) and methamidophos (0.45 liters a.i. ha-1), both independently and in combination, on arthropods in plots of common bean. The experiment was repeated for two growing seasons. Principal response curve, richness estimator, and Shannon–Wiener diversity index analyses were performed. The insecticides generally affected the frequency, richness, diversity, and relative abundance of the arthropods. In addition, the arthropods did not experience recovery after the insecticide applications. The results suggest that the insecticide impacts were sufficiently drastic to eliminate many taxa from the studied common bean plots.  相似文献   

10.
《Field Crops Research》2004,90(1):35-45
Traditional breeding efforts are expected to be greatly enhanced through collaborative approaches incorporating functional, comparative and structural genomics. Potential benefits of combining genomic tools with traditional breeding have been a source of widespread interest and resulted in numerous efforts to achieve the desired synergy among disciplines. The International Center for Tropical Agriculture (CIAT) is applying functional genomics by focusing on characterizing genetic diversity for crop improvement in common bean (Phaseolus vulgaris L.), cassava (Manihot esculenta Crantz), tropical grasses, and upland rice (Oriza sativa L.). This article reviews how CIAT combines genomic approaches, plant breeding, and physiology to understand and exploit underlying genetic mechanisms of abiotic stress adaptation for crop improvement. The overall CIAT strategy combines both bottom-up (gene to phenotype) and top-down (phenotype to gene) approaches by using gene pools as sources for breeding tools. The strategy offers broad benefits by combining not only in-house crop knowledge, but publicly available knowledge from well-studied model plants such as arabidopsis [Arabidopsis thaliana (L.) Heynh.]. Successfully applying functional genomics in trait gene discovery requires diverse genetic resources, crop phenotyping, genomics tools integrated with bioinformatics and proof of gene function in planta (proof of concept). In applying genomic approaches to crop improvement, two major gaps remain. The first gap lies in understanding the desired phenotypic trait of crops in the field and enhancing that knowledge through genomics. The second gap concerns mechanisms for applying genomic information to obtain improved crop phenotypes. A further challenge is to effectively combine different genomic approaches, integrating information to maximize crop improvement efforts. Research at CIAT on drought tolerance in common bean and aluminum resistance in tropical forage grasses (Brachiaria spp.) is used to illustrate the opportunities and constraints in breeding for adaptation to abiotic stresses.  相似文献   

11.
Crop rotation can be an effective mechanism for reducing disease incidence and contributing nitrogen (N) to succeeding crops. Interactions of plant pathogen suppression and soil nutrient availability may also exist, adding to the cropping system complexity. This study examined the impact of crop rotation, N fertilization, and their interaction on growth, yield, andRhizoctonia solani incidence in potato (Solanum tuberosum L. Norwis). Potato was grown continuously and in two-year rotations with annual alfalfa (Medicago sativa L. Nitro), hairy vetch (Vicia villosa Roth), white lupin (Lupinus albus L. Ultra), and oat (Avena sativa Astro). Fertilizer was banded at potato planting with 0, 45, 90, 135, 180, or 225 kg N ha?1 as (NH4)2SO4. Approximately 58% of continuous potato possessed stem lesions caused byR. solani, but only 12 to 22% of potato stems from other rotations possessed lesions. Tuber dry weight was affected by crop rotation in 1989, a dry year, but not in 1990. Apparent N fertilizer replacement values for hairy vetch, Nitro alfalfa, white lupin, and oat were 65, 43, 26, and 11 kg N ha?1, respectively. All crop rotations studied appeared to enhance potato production by reducing stem infection byR. solani. Vetch and alfalfa provide additional benefits through their N contributions.  相似文献   

12.
Faba bean is an excellent candidate crop to provide nitrogen input into temperate agricultural systems. However, its growth is hampered by several factors including environmental stresses and the presence of anti-nutritional factors. To solve these limitations, breeding programs have been initiated that were successful for monogenic traits but not so for multigenic traits. The large genome size of faba bean has slowed down breeding processes. Several other legumes have emerged as model legumes including Medicago truncatula, Lotus japonicus, Glycine max and Pisum sativum. The establishment of these models has already boosted our understanding of important processes such as the nitrogen-fixing symbiotic interaction. The high level of synteny and collinearity existing between legumes makes possible the transfer of key knowledge from model legumes to faba bean. Here we review the most recent knowledge gained from model legumes on grain quality, resistance to biotic and abiotic stresses, nitrogen-fixing symbiosis and how this knowledge can be employed for faba bean breeding.  相似文献   

13.
An experiment was conducted to determine the influence of crop rotations on soil seed bank to provide a comparison between crop fields and non-crop lands. Crop rotations were continuous dryland wheat (Wd), continuous irrigated wheat (Wi), wheat-sugarbeet (WS) and wheat-chickpea (WCh). Nearby pastures (P) and orchards (Or) were also studied for comparison purposes. Estimates of the density of seed banks ranged from 52779 seed m−2 in P to 9906 seeds m−2 in Wd. A total of 114 plant species from 24 families were identified from seeds collected from different farms. 33 weed species were at high frequency in weed communities. Crop rotations were dominated by annual weed species, while the weed species dominated in P were mostly not found in any crop rotation. The two weed species Roemeria refracta and Eragrostis cilianensis were frequently present in all the study sites. Amaranthus chlorostachys and Euphorbia esula were more abundant in the areas of moderate to high disturbance. In SW and WS rotations, due to use of grass herbicides and hand weeding, winter annual broadleaves such as Lactuca serriola and Anchusa italica were the prominent species in the seed bank. Results showed that a number of weed species are adapted to a specific crop sequences and disturbance levels. Weed species richness, seed bank abundance and diversity in soil depths are highly dependent on disturbance levels. The current study highlights the importance of agricultural practices including crop sequences or disturbance levels in determining the characteristics of weed populations. This provides useful information to improve methods for maintaining plant population balance.  相似文献   

14.
Bean fly (Ophiomyia spp.) is a major field pest limiting common bean production in eastern Africa. The genetic enhancement of beans for resistance to insect pests is essential for minimizing yield losses arising from crop damage. The objectives of this study were to (1) assess combining ability for bean fly resistance and seed yield accumulation in common bean and (2) estimate genetic parameters associated with resistance for formulating further breeding strategy. Four parents with known reaction to bean fly were crossed with four locally adapted genotypes in an 8 × 8 half diallel mating design. Parents and F2 progenies were grown in an alpha-lattice design replicated twice in an open-field and subjected to natural populations of bean fly for two cropping seasons under semi-arid conditions. Similarly, two resistant and two susceptible parents were selected and crossed to produce populations for generation means and variances components analysis. Results revealed that both general combining ability (GCA) and specific combining ability (SCA) mean squares were significant (p ≤ 0.05) for all four traits studied except SCA for stem damage during one cropping season. Among the parents, GBK 047858 was the best general combiner for all the traits studied across seasons except for stem damage during long rains (LR) 2009. Besides, genotypes GBK 047821 and Kat × 69 (a locally adapted variety) were generally good general combiners for resistance traits as well as seed yield. General predictability ratio (GPR) values ranging from 0.63 to 0.90 were obtained for plant mortality, stem damage, pupae in stem and seed yield across cropping seasons. These results established the predominance of additive gene effects (fixable variation) over the non-additive effects in controlling the traits. Low to moderate narrow sense heritability values ranging from 0.22 to 0.45 were obtained for pupae in stem. Such heritability estimates indicate that although additive gene components were critical in the inheritance of resistance for the trait, non-additive gene action were also important in addition to the environmental effects.  相似文献   

15.
《Field Crops Research》1998,57(3):265-276
The grain quality of wheat is influenced by the protein content, which in turn depends on environmental conditions and cropping practices. We carried out a 3-year field study in a rainfed Mediterranean region on the effects of tillage, crop rotation and nitrogen fertilization on the grain quality of hard red spring wheat (Triticum aestivum) in terms of protein content, test weight and alveogram indices. Tillage treatments were no tillage (NT) and conventional tillage (CT). Crop rotations were wheat–sunflower (Helianthus annus L.) (WS), wheat–chickpea (Cicer arietinum L.) (WCP), wheat–fababean (Vicia faba L.) (WFB), wheat–fallow (WF) and continuous wheat (CW). Fertilizer nitrogen was used at three different rates: 50, 100 and 150 kg N ha−1. A split–split plot design with four replicates was used. Grain protein content was found to be inversely proportional to rainfall during the growing season. The tillage method was also found to affect grain protein content, test weight and some grain quality indices. Through its effect on moisture and nitrate in the soil. The crop rotations that included a legume (WCP and WFB) had marked effects on wheat quality. The increased grain protein content and resulted in improved rheological properties of the dough (viz. a higher alveogram index and a more balanced tenacity/extensibility ratio). However, no differences due to N dilution in the plant were observed in the wettest year studied, which was also the highest yielding. Increasing the fertilizer N rate increased the grain protein content; this variable had the most marked influence on grain quality indices, though in the year that gave the highest yield the N dilution effect was observed. The many significant interactions among experimental variables reveal a close relationship among grain yield, protein content, grain quality and the wheat growth conditions. Specifically, the amount of rainfall and its distribution in the growing season strongly influenced N availability and uptake by the crop, as well as wheat-grain quality indices.  相似文献   

16.
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17.
Potato nutrient management in sustainable cropping systems   总被引：2，自引：0，他引：2  
Sustainable nutrient management involves a set of management practices designed to conserve soil resources, to maintain or enhance productivity, and to help reduce growers’ reliance on chemical fertilizers. Sustainable nutrient management systems will most certainly rely heavily on the use of legume rotation crops and/or organic soil amendments. To realize the full benefit to the crop ecosystem, sustainable nutrient management programs will also likely require longer crop rotations with less frequent potato production. There is considerable research evidence indicating that these systems can maintain or increase productivity while having positive impacts on nutrient supply, soil physical properties, and soil conservation. However, their successful adoption and continued use on a large scale will require resolution of uncertainties related to economic risk associated with inconsistent nutrient availability in alternative nutrient management systems, potential environmental risks associated with excessive P applications in animal manures, and the potential for increased potato pest incidence resulting from manure application.  相似文献   

18.
Two common production constraints of dry bean (Phaseolus vulgaris) in Ontario are annual weeds and anthracnose (caused by Colletotrichum lindemuthianum). Dry bean is not considered a competitive crop and weed interference can result in substantial yield losses, while anthracnose is considered one of the most devastating diseases in dry bean production. A study conducted in Ontario Canada, examined the effect of two herbicide programs on weed management, thiamethoxam insecticide treatment on plant enhancement and three fungicide programs on anthracnose development in a navy bean cv. ‘OAC Rex’. The premium herbicide program (s-metolachlor + imazethapyr) reduced percent weed ground cover relative to the economic herbicide program (trifluralin) in five of six locations. Thiamethoxam increased emergence and vigour at only one location, which contradicts reported benefits of thiamethoxam on plant health. The herbicide or thiamethoxam treatments did not affect anthracnose disease severity, visible seed quality, net yield or economic return. The fungicide seed treatment was often superior to the untreated control, for a number of the parameters measured. The application date of the foliar fungicide, relative to the onset of disease, varied between site-years. This dramatically influenced the fungicide’s effectiveness. Foliar fungicides increased seed quality and net economic return compared to the control when applied prior to disease development. The combination of fungicide seed treatment followed by a foliar fungicide provided the largest reduction in anthracnose severity.  相似文献   

19.
Smallholder farmers in sub-Saharan Africa are confronted by low productivity and limited investment capacity in nutrient inputs. Integrated soil fertility management (ISFM) aims at increased productivity through the combined use of improved germplasm, judicious fertilizer application and organic matter management, adapted to the local farming conditions. We hypothesize that the application of these different ISFM components can result in significant increases in productivity and economic benefits of cassava–legume intercropping systems. Participatory demonstration trials were conducted in the highlands of Sud-Kivu, DR Congo with 12 farmer groups during 3 seasons. Treatments included the farmers’ common practice (local common bean and cassava varieties, seed broadcast and manure addition) and sequentially added ISFM components: improved bean and cassava germplasm, modified crop arrangements, compound NPK fertilizer application and alternative legume species (groundnut or soybean). The use of improved germplasm did not result in yield increases without simultaneous implementation of other ISFM components. Modifying the crop arrangement by planting cassava at 2 m between rows and 0.5 m within the row, intercropped with four legume lines, increased bean yields during the first season and permits a second bean intercrop, which can increase total legume production by up to 1 t ha−1 and result in an additional revenue of almost 1000 USD ha−1. Crop arrangement or a second legume intercrop did not affect cassava storage root yields. Fertilizer application increased both legume and cassava yield, and net revenue by 400–700 USD ha−1 with a marginal rate of return of 1.6–2.7. Replacing the common bean intercrop by groundnut increased net revenue by 200–400 USD ha−1 partly because of the higher market value of the grains, but mostly due to a positive effect on cassava storage root yield. Soybean affected cassava yields negatively because of its high biomass production and long maturity period; modifications are needed to integrate a soybean intercrop into the system. The findings demonstrate the large potential of ISFM to increase productivity in cassava–legume systems in the Central-African highlands. Benefits were, however, not observed in all study sites. In poor soils, productivity increases were variable or absent, and soil amendments are required. A better understanding of the conditions under which positive effects occur can enable better targeting and local adaptation of the technologies.  相似文献   

20.
Faba bean in cropping systems   总被引：1，自引：0，他引：1  
The grain legume (pulse) faba bean (Vicia faba L.) is grown world-wide as a protein source for food and feed. At the same time faba bean offers ecosystem services such as renewable inputs of nitrogen (N) into crops and soil via biological N2 fixation, and a diversification of cropping systems. Even though the global average grain yield has almost doubled during the past 50 years the total area sown to faba beans has declined by 56% over the same period. The season-to-season fluctuations in grain yield of faba bean and the progressive replacement of traditional farming systems, which utilized legumes to provide N to maintain soil N fertility, with industrialized, largely cereal-based systems that are heavily reliant upon fossil fuels (=N fertilizers, heavy mechanization) are some of the explanations for this decline in importance. Past studies of faba bean in cropping systems have tended to focus on the effect of faba bean as a pre-crop in mainly cereal intensive rotations, whereas similar information on the effect of preceding crops on faba bean is lacking. Faba bean has the highest average reliance on N2 fixation for growth of the major cool season grain legumes. As a consequence the N benefit for following crops is often high, and several studies have demonstrated substantial savings (up to 100–200 kg N ha−1) in the amount of N fertilizer required to maximize the yield of crops grown after faba bean. There is, however, a requirement to evaluate the potential risks of losses of N from the plant–soil system associated with faba bean cropping via nitrate leaching or emissions of N2O to the atmosphere as a consequence of the rapid mineralization of N from its N-rich residues. It is important to develop improved preventive measures, such as catch crops, intercropping, or no-till technologies, in order to provide farmers with strategies to minimize any possible undesirable effects on the environment that might result from their inclusion of faba bean in cropping system. This needs to be combined with research that can lead to a reduction in the current extent of yield variability, so that faba bean may prove to be a key component of future arable cropping systems where declining supplies and high prices of fossil energy are likely to constrain the affordability and use of fertilizers. This will help address the increasing demand by consumers and governments for agriculture to reduce its impact on the environment and climate through new, more sustainable approaches to food production. The aims of this paper are to review the role of faba bean in global plant production systems, the requirements for optimal faba bean production and to highlight the beneficial effects of faba bean in cropping systems.  相似文献   

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