Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 2 of 2

Full-Text Articles in Physical Sciences and Mathematics

An Integrated Crop- And Soil-Based Strategy For Variable-Rate Nitrogen Management In Corn, Darrin F. Roberts Aug 2009

An Integrated Crop- And Soil-Based Strategy For Variable-Rate Nitrogen Management In Corn, Darrin F. Roberts

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Nitrogen (N) management in cereal crops has been the subject of considerable research and debate for several decades. Historic N management practices have contributed to low nitrogen use efficiency (NUE). Low NUE can be caused by such things as poor synchronization between soil N supply and crop demand, uniform application rates of fertilizer N to spatially variable landscapes, and failure to account for temporally variable influences on soil N supply and crop N need. Active canopy reflectance sensors and management zones (MZ) have been studied separately as possible plant- and soil-based N management tools to increase NUE. Recently, some have …


Soil Carbon And Nitrogen Accumulation In A Forested Debris Flow Chronosequence, California, Judith K. Turk, Robert C. Graham Jan 2009

Soil Carbon And Nitrogen Accumulation In A Forested Debris Flow Chronosequence, California, Judith K. Turk, Robert C. Graham

Conservation and Survey Division

The role of forest soils in the biogeochemical cycling of C and N is most dynamic during the early stages of soil development. To define C and N trends that occur with soil development in a mixed coniferous forest, a chronosequence formed by debris flows was studied. The accumulation rates of total organic C (TOC) and total N (TN) were evaluated in soils on 10 debris flow deposits, ranging from depth, since this was the depth of the shallowest debris flows. Carbon was found to accumulate in the organic horizons at a rate of 26.5 g m−2 yr−1 …