Nutrient and microbial transport by runoff may vary at different locations within a beef cattle feedlot. If the areas making the largest contributions to nutrient and microbial transport can be identified, it may be possible to institute site‐specific management practices to reduce runoff nutrient and microbial transport. The objectives of this study were to: (1) measure selected feedlot soil p...

Alfred Hartemink is a soil scientist at ISRIC in Wageningen. Prior to his current position he was lecturer in soil science at the University of Technology in Papua New Guinea. He holds an MSc in soil science from Wageningen Agricultural University, and has worked as a soil surveyor and soil fertility specialist in Tanzania, Zaire, Indonesia, and for ICRAF in Kenya. Dr Mike Bourke is an Adjunct ...

Soil nutrient is an important aspect that contributes to the soil fertility and environmental effects. Traditional evaluation approaches of soil nutrient are quite hard to operate, making great difficulties in practical applications. In this paper, we present a series of comprehensive evaluation models for soil nutrient by using support vector machine (SVM), multiple linear regression (MLR), an...

Drought and shortages of soil water are becoming extremely severe due to global climate change. A better understanding of the relationship between vegetation type and soil-moisture conditions is crucial for conserving soil water in forests and for maintaining a favorable hydrological balance in semiarid areas, such as the Saihanwula National Nature Reserve in Inner Mongolia, China. We investiga...

Cropping systems models have evolved over the last four decades in response to the demand for modeling to address more complex questions, including issues on sustainable production, climate change, and environmental impacts. Early models, which were used primarily for yield gap analysis, have increased in complexity to include not only nutrient and water deficiencies, but also pest and disease ...

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...

Canonical correlation analysis was applied to the study of interrelationships between two multivariate datasets, one consisting of available and exchangeable potassium content, and second consisting of pH, hydrolytic acidity, and content of exchangeable aluminum, calcium and magnesium, available phosphorus, and total nitrogen. An attempt has been made to provide an overall pattern of interrelat...

Biogeochemical properties, including nutrient concentrations, carbon gas fluxes, microbial biomass, and hydrolytic enzyme activities, were determined along a strong nutrient gradient in an ombrotrophic peatland in the Republic of Panama. Total phosphorus in surface peat decreased markedly along a 2.7 km transect from the marginal Raphia taedigera swamp to the interior sawgrass swamp, with simil...

Over the past 20 years, the use of center-pivot irrigation has increased tomato (Solanum lycopersicum L.) yields in Brazil from 42 Mg ha-1 to more than 80 Mg ha-1. In the absence of field trials to support fertilizer recommendations, substantial amounts of phosphorus (P) have been applied to crops. Additional P dosing has been based on an equilibrated nutrient P budget adjusted for low-P fertil...