Submitted to: Southern Association of Agricultural Scientists Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 2/4/1996
Publication Date: N/A
Technical Abstract: Pasture productivity within a given plant species depends on soil fertility, defoliation frequency and intensity, and climate (water and temperature). Sustainable pasture systems require N addition through fertilizers, wastes, or dinitrogen fixation. This presentation reviews management effects on N fractions in improved pasture plants. Nitrate in plant tissue is an indicator of adequacy of N nutrition. Plant tissue N03-N in excess of 600 mg/kg suggests adequate N nutrition when conditions are favorable for growth. When environmental factors such as drought, low light intensity inhibit carbon assimilation under conditions of available soil NO3, NO3 reduction to protein is also reduced, resulting in NO3 accumulation in plant tissue. Management effects include choice of plants, degree of defoliation, fertilization including animal waste application, and interactions of these effects with climatic factors of temperature and water. Examples from research at the Southern Piedmont Conservation Research Center will be presented.