In dryland cropping systems, optimal yields require that nutrient supply matches the soil’s yield potential supported by available moisture. Conservation tillage systems that leave at least 30 percent of the soil surface covered by residue dramatically increase moisture retained in the soil compared to crop-fallow systems. This enables producers to plant two, three, or four consecutive crops, o...

Elevated atmospheric carbon dioxide (CO2) can affect both the quantity and quality of plant tissues produced, which will impact the cycling and storage of carbon (C) within plant/soil systems and thus the rate of CO2 release back to the atmosphere. Research is needed to more accurately quantify the effects of elevated CO2 and associated feedbacks on soil CO2 efflux in order to predict the poten...

Trecs can he considered as investments made by economic agents to prevent depreciation of natural assets such as stocks of top soil and water. In agroforestq systems farmers use trees in this manner by deliberately combining them with agricultural crops on the same unit of land. Although advocates of agroforestry have asserted that soil conservation is one of its primary henefits, empirical est...

In the United States, government sponsored conservation programs are under increasing pressure to quantify the environmental benefits of practices they subsidize. To meet this objective, conservation planners need tools to accurately predict phosphorus (P) loss from agricultural lands. Existing P export coefficient based tools are easy to use, but do not adequately account for local conditions....

BACKGROUND Changes in agricultural practices-notably changes in crop varieties, application of fertilizer and manure, rotation and tillage practices-influence how much and at what rate carbon is stored in, or released from, soils. Quantification of the impacts of land use on carbon stocks in sub-Saharan Africa is challenging because of the spatial heterogeneity of soil, climate, management cond...

The magnitude and extent of soil erosion in the Pacific Northwest region of the US still makes chilling reading. In a conventional farming approach in land mostly planted to winter wheat, there can be a loss of 12 bushels of topsoil, mostly from water erosion, for each bushel of wheat produced, with on-site losses of up to 1/8 in. of this highly fertile topsoil. Off-site outcomes were equally d...