Evaluation of Poultry Manure and Fertilizer N for Corn in a Strip Test

in HortScience
Author: John D. Downes1
View More View Less
  • 1 Texas Tech University, 1231 Miami Street, Athens, TN 37303

Animal waste disposal from large operations is an increasing problem, and its value as a fertilizer needs to be determined. Strip tests often are unreplicated creating problems in analysis. In an unreplicated Georgia farm test involving a three manure (0, 1, 2 loads/acre) × 3 N (0, 70, 90 lb/acre) factorial on corn yield from the control plot was not included, making n = 8, and precluding the usual ANOVA and means comparisons. Partial budget analysis is compared to regression analysis and economic evaluation at varying input costs and corn prices. Best estimates were obtained by finding the N equivalent of manure [(56.4 lb N)/load] and regressing yield on sum of N (Nf + Nm), which estimated Y = –14.0 + 1.1724N – 0.00324NN, RR = .982, F = 136.38, P > F =.000, sye = 3.0 bushel/acre, from which Nmax = 181, Ymax = 92.1 bushel/acre. Nopt varied from 139 to 172 bushel/acre with cost N varying from $0.14/lb (manure cost) to $0.40/lb, and corn prices from $1.50 to $2.50/bushel. Manure thus valued at 16.92 per load when costing $8.00, assuming 56.4 lbs/load N. Major point was estimation N equivalent of manure from yield effects and then regression yield on N. Equation easily converted to one in M.

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 35 6 0
PDF Downloads 71 28 10