New Or Revised Nebraska Extension Crop Production Publications

• Planning the Transition to Organic Crop Production (G2282). A guide to moving from conventional to certified organic production, including focus on farm and financial resources, record keeping, and transition strategy. Authors: Charles S. Wortmann, Extension soils specialist; Richard S. Little, research technologist; Colin J. Kubik, former M.S. graduate student; Charles A. Shapiro, Extension soils specialist–crop nutrition; Charles A. Francis, professor of agronomy and horticulture.

• Soil Management for Increased Soil Organic Matter (G2283). Soil organic matter (SOM) affects many soil properties and processes. For given climate, soil, and management conditions, SOM moves toward a steady state level. Sustained increases of SOM above the steady state level may not be feasible. Substantial SOM increases can be expected when SOM is below steady state, but little increase above the steady state can be expected without a change in climate, soil, or management. Management practices such as erosion control, tillage, crop residue management, rotations, cover crops, and manure application are discussed for increasing SOM and for shifting the steady state upward. Authors: Charles S. Wortmann, Extension soils specialist; Juan Pablo Garcia, Ph.D. graduate student; Charles A. Shapiro, Extension soils specialist; Tim M. Shaver, Extension soils specialist; Richard B. Ferguson, Extension soils specialist; Bijesh Maharjan, Extension soils specialist; Humberto Blanco, soils specialist; Sabrina Ruis, post-doctoral researcher; and Richard S. Little, research technologist. 

• Observed Space and Time Changes in Air Temperatures and Daily Temperature Range for the USA Great Plains Counties from 1968 to 2013 (EC3009). Understanding the magnitude and direction of potential changes in climate variables is important to better understand the relationships between these changes and agricultural production, water resources, irrigation practices, and related topics. Better evaluation of the relationships between climate variables and agriculture also requires studying these relationships on large scales. This Nebraska Extension Circular presents scientific data, analyses, and interpretation using visual maps and discussion of:

1. geographic variability (trends) that exists in patterns of historical air temperatures (maximum, minimum, and average) and daily temperature range across the United States Great Plains;
2. the temporal (1968–2013) changes that have been observed in these variables; and
3. potential consequences and significance of these changes in light of agricultural production in the Great Plains.

The study region comprises nine states and 834 counties from Texas to North Dakota and from Iowa to Colorado and is about 30% of the surface area of the continental United States. Authors: Meetpal S. Kukal, graduate research  assistant; Suat Irmak, oil and water resources and irrigation engineer. 

• Management of Phytophthora Root and Stem Rot of Soybean (G1785). Discusses symptoms, favorable environmental conditions, management, and genetic resistance and includes several tables including a table of seed treatment fungicides labeled for phytophthora sojae control on soybean. Authors: Loren J. Giesler, Exension plant pathologist, Kyle C. Broderick, research technologist, plant pathology