Cropping diversification with cover crop mixtures combined low N fertilization represents an ecological alternative that may promote sustainability. Our objective was to evaluate changes on soil organic fractions and structure, biomass, main yield 5 years after the introduction of two mixtures, oats+forage radish (CC1) radish+vetch (CC2), in a soybean-soybean maize-soybean sequence maize. After...

Research techniques that have greatly advanced agronomic science in the 20th century, and have enhanced our knowledge of cause and effect, have been accompanied by reductionism. As a result, much valuable research has been accomplished, but less synthesis of results has occurred that provides answers to landscape-level research questions. We propose that a systems approach to the study of soil ...

The widely accepted models describing the emergence of domesticated grain crops from their wild type ancestors are mostly based upon selection (conscious or unconscious) of major features related either to seed dispersal (nonbrittle ear, indehiscent pod) or free germination (nondormant seeds, soft seed coat). Based on the breeding systems (self-pollination) and dominance relations between the a...

Intensive vegetable cropping systems use large amounts of water and nutrients. Excess application of water and nutrients results in economic losses (higher fertilizers and pumping costs) and contributes to nutrient leaching and environmental degradation. Increasing nutrient use efficiency (NUE) and water use efficiency (WUE) should be a priority for sustainable horticulture. This increased NUE,...

Sweetpotato (Ipomea batatans) is a food crop of global significance. The storage roots and foliage of crop are attacked by a wide range of pests and diseases. Whilst these are generally well controlled in developed countries using approaches such as clean planting material and monitoring with pheromone traps to guide insecticide use, research into methods suitable for developing countries has l...

Emissions of nitric oxide (NO) were measured during the summer of 1995 from 4 crops, located at three different sites throughout North Carolina. These sites were chosen to represent major physiographic regions of the Southeast US, in an effort to compare fluxes from different agriculturally managed soils. Emission rates were determined using a dynamic flow-through chamber system. In order to un...

Several studies have concluded that mountainous countries such as Nepal are more vulnerable to climate change; thus, a changing climate should have a significant impact on crop yields. This work aims to explore the impact of climate change on major crop yields in the mountainous parts of Nepal and to determine their relationships based on a regression model between historical climatic data and ...