Joseph M. Krupinsky

Dynamic Cropping Systems

Cropping systems need to be inherently flexible to take advantage of economic opportunities and/or adapt to environmental realities. A dynamic cropping systems concept-characterized by a management approach whereby crop sequencing decisions are made on an annual basis-has been proposed to improve the adaptability of cropping practices to externalities. A symposium on dynamic cropping systems was held at the 2005 ASA-CSSA-SSSA annual meetings in Salt Lake City, UT. Presentations at the symposium reviewed research results from a recent experiment near Mandan, ND, investigating short-term crop sequence effects on crop production, plant diseases, soil residue coverage, and soil water depletion. This paper briefly reviews each of the presentations at the symposium. Future research opportunities on dynamic cropping systems abound, and may have increased impact if emerging issues in agriculture (e.g., increased use of biofuels; livestock integration in cropping systems) are incorporated in evaluations.

Chlorophyll meter as nitrogen management tool in malting barley

Abstract Variable precipitation in many regions makes it difficult to predict yield goals and nitrogen (N) rates for malting grade barley (Hordeum vulgare L.). During years with below normal growing season precipitation, barley fertilized at the recommended rate often exhibits grain protein concentrations exceeding what is acceptable for malting. A study was conducted to evaluate the chlorophyll meter as a N management tool. Barley was grown under several N rates in the field. Chlorophyll meter readings and N additions were made at the Haun 4 to 5 growth stage, and grain yield and protein concentrations were evaluated at maturity. Chlorophyll meter readings, normalized as meter reading from treatment plot divided by that from a plot receiving a full N treatment at the Haun 4 to 5 growth stage, were correlated with grain yield (r2=0.67). Stands having normalized chlorophyll meter readings below 95% responded to N additions with yields equivalent to the fully fertilized stand and grain protein concentration...