ABSTRACT Eight different 3-year cropping systems, consisting of soybean-canola, soybean-barley, sweet corn-canola, sweet corn-soybean, green bean-sweet corn, canola-sweet corn, barley-clover, and continuous potato (non-rotation control) followed by potato as the third crop in all systems, were established in replicated field plots with two rotation entry points in Presque Isle, ME, in 1998. Cro...

It is important to understand the underlying factors that lead to shifts in soil microbial communities, not simply for the characterization of these complex biotic systems, but also to understand the impact that changes in microbial community composition may have on terrestrial ecosystems. In this study, the impact of genetically different potato (Solanum tuberosum) plants growing in arable soi...

There is need for proper understanding of plant nutrients status in the soil and their requirements by various crops under different farming system. Farmers must be encouraged to make compost from residues, house refuse and other decomposable wastes available with them. If crop residues have been incorporated into the soil, care must be taken that it must be incorporated well in advance (about ...

Landscape-scale variation is a source of information that increasingly is being taken into consideration in agricultural and environmental studies. Models that encompass and interpret this variation in ®elds and across contrasting management practices have the potential to improve the landscape management of agroecosystems. Our objective was to compare the results of two approaches, analysis of...

Long-term use of fallow in dryland wheat (Triticum aestivum L.) systems can increase erosion and decrease soil fertility. One possible solution is to grow a green manure crop during the fallow period. To evaluate the short-term effects of substituting a winter legume green manure for fallow in a 2-vr wheat rotation, a series of experiments were conducted in the Sacramento Valley of California f...

Soil-incorporated rotation/green manure crops were evaluated for management of potato early dying caused by Verticillium dahliae and Pratylenchus penetrans. After two years of rotation/green manure and a subsequent potato crop, P. penetrans numbers were less after 'Saia' oat/'Polynema' marigold, 'Triple S' sorghum-sudangrass, or 'Garry' oat than 'Superior' potato or 'Humus' rapeseed. The area u...

Cropping systems based on carefully designed species mixtures reveal many potential advantages in terms of enhancing crop productivity, reducing pest and diseases, and enhancing ecological services. Associating cereals and legume production either through intercropping or rotations might be a relevant strategy of producing both type of culture, while benefiting from combined nitrogen fixed by t...

Soil organic C (SOC) and total N (TN) contents play a crucial role in sustaining agricultural production systems. Short-term ( 10-year) management effects on SOC and TN dynamics are often complex and variable. Three experiments were conducted to evaluate short-term tillage and cropping system effects on SOC and TN within the 0–30 cm soil depth across Iowa. The first experiment with no-tillage a...

An important aspect for estimating optimal N applications is to predict the soil N supply capacity (ability to supply plant-available N) each year. Since fertilizer applications supplement crop N requirements that the soil system cannot meet, understanding potential plant-available N originating from the soil can aid in setting N fertilization rates. General differences in plantavailable N and ...