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Rotation versus monoculture of irrigated corn crops in relation to energy input and economic return
Abstract
Current economic conditions in agriculture and environmental concerns over ground water pollution have producers seeking more efficient methods of crop production. Agriculture has also become very dependent upon fossil fuels for inputs such as nitrogen fertilizer and irrigation water application. A field experiment was initiated in 1982, at Mead, NE, to examine the effects of manure and increasing levels of N, P, K, and micronutrients on grain yield, return over variable costs (ROVC), and energy input of a corn(Zea mays L.)-soybean(Glycine max L.)-wheat(Triticum aestivum L.) rotation (CSW) versus continuous corn (CC). Rotation corn (RC) grain yields were 20 percent higher than CC at optimum N-rate. Fertilizer N and P increased corn and wheat yields, respectively, but soybean yields were unaffected by fertilizer nutrients. Corn and wheat grain protein content were related to the rate of N applied. Residual NO$\sb3$-N levels were low regardless of previous crop where no N was applied, when 320 lb N a$\sp{-1}$ was applied to corn, residual levels ranged from 91 to 491 lb a$\sp{-1}$. Continuous corn ROVC was slightly lower than ROVC for CSW, however, the variability of ROVC was less for CSW than CC indicating that a measure of risk avoidance could be attained by growing a rotation of crops. Energy input requirements for CC, RC, soybean, and wheat were 3183, 3271, 1123, and 763 Mcal a$\sp{-1}$ respectively. Nitrogen fertilizer (33%) and irrigation (28%) accounted for the greatest use of energy for corn production. Analysis of costs of production showed that CC was more affected by energy price increases than CSW. Growing corn in a rotation provides yield advantages and also reduces the variability of income from year to year. Soil test levels of nutrients were increased by seven years of manure or fertilizer addition, but crop yields were not influenced by the increase. The sufficiency concept for fertilizer recommendations represents the best management approach to account for changes in soil nutrient levels.
Subject Area
Agronomy
Recommended Citation
Peterson, Wallace Richard, "Rotation versus monoculture of irrigated corn crops in relation to energy input and economic return" (1989). ETD collection for University of Nebraska-Lincoln. AAI9013621.
https://digitalcommons.unl.edu/dissertations/AAI9013621