Relationship Between Corn Yield, Expressed as a Percentage of Maximum, and the N Percentage in the Grain. I. Various N‐rate Experiments¹

Abstract

The objective of this investigation was to determine if the N content of the grain of corn (Zea mays L.) could be used as a measure of N sufficiency of the crop for maximum yield. This was done by studying the relationship between yield, expressed as a percentage of maximum, and the N percentage in the grain. The relationship was determined from the data of 13 site‐years of six N‐rate experiments in Iowa and from data reported in the literature. Two methods, a graphical and a regression method, were developed to relate the yield of corn, expressed as a percentage of maximum, and the N percentage in the grain. Good agreement was found between the two methods for obtaining maximum yields and N percentages at various percentages of maximum yield. The average critical N percentages, or percentages at maximum yield, by the graphical and regression methods, were 1.52% and 1.54%, respectively, for the Iowa experiments. The data calculated from the experiments reported in the literature were in general agreement with the Iowa data. The standard error of the mean of the critical N percentages (graphical method) for the 13 site‐years of Iowa experiments was 0.016% and, for the 24 site‐years of the non‐Iowa experiments, it was 0.022%. Some of the variability may have been caused by differences among the 23 hybrids represented in the experiments. Moisture stress, plant density, and adequacy of other nutrients had little or no demonstrable effect on the relative yield — percent N relationship. It is concluded that the relative yield — percent N relationship offers a promising and practical basis for estimating N sufficiency and the N requirement for maximum yield, or for an economic optimum yield.

Tillage system effects on 15-year carbon-based and simulated N budgets in a tile-drained Iowa field

“…Annual N removal by the grain was estimated by adjusting the yield to zero g kg À1 water content and multiplying by the average 1992 grain N concentrations (12.9, 12.6, 12.2, and 11.3 (g N) kg À1 for moldboard plow, chisel plow, ridge-tillage, and no-tillage practices, respectively). Grain N concentrations were not measured during the other years, but the values for 1992 were within the range reported by Pierre et al (1977) for corn grown in N-rate studies throughout Iowa, USA.…”

Estimating nitrogen fertiliser requirements in maize grain production

“…This is comparable to figures of 1.52 and 1.54% reported by Pierre et al (1977a). Insufficient trials were sampled in the Waikato to permit a valid comparison between seasons, but Pierre et al (1977a) suggested that moisture stress had little if any effect on the % N value between 70 and 100 % relative yield.…”

“…This is comparable to figures of 1.52 and 1.54% reported by Pierre et al (1977a). Insufficient trials were sampled in the Waikato to permit a valid comparison between seasons, but Pierre et al (1977a) suggested that moisture stress had little if any effect on the % N value between 70 and 100 % relative yield. Relative yield-percent N relationships for grain calculated from published results covering 15 hybrids and a range oflocations and plant populations showed that the % N associated with maximum yield ranged from 1.38 to 1.77 (mean 1.53) (Pierre et al 1977a).…”

SimPLE.ca: Simulator of productivity loss due to erosion for Canada

“…(1 grain for wheat based on ratios of crop components to grain yield (Bolinder et al 2007b) and N concentrations derived from literature sources (Pierre et al 1977;Wichmann 1998;Canadian Fertilizer Institute 2001;Preston 2002 Available N was derived from organic N mineralization, atmospheric N deposition and N fertilizer application. Total deposition of atmospheric N was estimated as a proportion of total annual precipitation (0.025 kg N mm…”