2016 journal article

Corn Yield and Grain Nutrient Uptake from 50 Years of Nitrogen and Phosphorus Fertilization

AGRONOMY JOURNAL, 109(1), 335–342.

By: A. Schlegel * & J. Havlin n

UN Sustainable Development Goal Categories
2. Zero Hunger (Web of Science; OpenAlex)
13. Climate Action (Web of Science)
15. Life on Land (Web of Science)
Source: Web Of Science
Added: August 6, 2018

Core Ideas Initiated in 1961, a 50‐yr field study quantified continuous irrigated corn response to annual N and P rates. Positive N–P interactions on grain yield and grain N/P concentrations were documented. Economic optimum N rate varied greatly over years, but averaged ∼175 kg N ha−1 (1992‐2010). Significantly greater apparent fertilizer N recovery in grain (∼45%) occurred with P fertilization compared to no P (∼20%). Long‐term field studies can be used to improve nutrient effects on productivity. Long‐term agricultural field experiments provide valuable information regarding the effects of nutrient inputs on crop productivity. The objectives of this study were to quantify the effects of 50 yr of annual N and P application on irrigated continuous corn (Zea mays L.) grain yield, grain nutrient uptake, and economic optimum N rates. Six N (0, 45, 90, 134, 179, and 224 kg N ha−1) and three P rates (0, 20, and 40 kg P ha−1) in a factorial arrangement were applied annually from 1992 to 2010 to a Ulysses silt loam near Tribune, KS. From 1961 to 1991, only two P rates (0 and 20 kg P ha−1) were applied with the six N rates. During the last 19 yr, grain yield increased 20% with P alone and 103% with N alone; however, N and P applied together increased grain yields up to 225% compared to the unfertilized control. The N rate required for maximum profit at 20 and 40 kg P ha−1 averaged 172 and 180 kg N ha−1, respectively. At the economic optimum N rate of 172 kg N ha−1, apparent fertilizer nitrogen recovery in grain (AFNRg) was 44% and apparent fertilizer phosphorus recovery (AFPRg) was 63 and 44% with 20 and 40 kg P ha−1, respectively. Fifty years of irrigated corn response to N and P fertilization demonstrated a strong positive interaction between N and P on grain yield, apparent N and P recovery, and profitability.