Impact of a New Deep Vertical Lime Placement Practice on Corn and Soybean Production in Conservation Tillage Systems

Theodore Blumenschein,Peter Motavalli,Kelly Nelson

doi:10.3390/agronomy8070104

Abstract

Agricultural soils utilized for corn (Zea mays L.) and soybean (Glycine max [L.] Merr.) production in the Midwestern U.S. are often managed to have adequate surface soil pH for crop growth, but the presence of acidic subsoils may limit crop production. Subsoil acidity may inhibit root growth, leading to decreased drought tolerance and grain yields. Application of aglime can increase soil pH, improve soil structure, and provide calcium and magnesium to the soil, but surface amendments that often occur in no-till systems rarely affect the subsoil, resulting in potential chemical and physical barriers to root growth. The objective of this study was to determine the effects of surface and a new deep vertical lime placement practice, at three application rates, on corn and soybean plant growth and yields in a conservation tillage system. Field trials were conducted from 2012 to 2016 in Northeast Missouri on a poorly-drained claypan soil with treatments of lime (0, 3.4, and 6.7 Mg ha−1) broadcast on the soil surface or applied as a deep vertical band to a depth of 51 cm. When precipitation was below average, compared to control plots, deep vertical placed lime at 6.7 Mg ha−1 significantly raised corn yields by 1.3 Mg ha−1 four years after treatment. In years with adequate precipitation, no significant increases in corn yield were observed with deep lime placement treatments compared to the control. Lime treatments had a greater effect on corn yield than soybean. Deep vertical placement of lime resulted in no significant increase in soybean yield compared to the controls for all trials. Longer observation time may be needed to fully evaluate the effects of these lime placement treatments.

Highlights

IntroductionAcidic conditions in the subsoil horizons have been shown to affect nutrient availability and root growth of many agronomic crops [2,8,9]
Effects of subsoil acidity on agronomic production is of great concern in multiple regions around the world [1,2,3,4,5,6], with roughly 70% of the world’s arable land having some level of soil acidity [7].Acidic conditions in the subsoil horizons have been shown to affect nutrient availability and root growth of many agronomic crops [2,8,9]
Ameliorating subsoil acidity impediments to root growth in conservation tillage systems using a novel deep vertical lime placement practice was assessed for corn and soybean production in a less weathered poorly-drained soil

Summary

Introduction

Acidic conditions in the subsoil horizons have been shown to affect nutrient availability and root growth of many agronomic crops [2,8,9]. Liming additions have been shown to increase grain yields of many crops through increased rooting systems, nutrient availability and uptake, drought resistance, and reduction of aluminum and manganese toxicities [1,4,5,14]. In the United States alone, it is estimated that roughly 73 million Mg of agricultural lime is required each year to neutralize acidity generated from crop removal [15]. It is estimated that under current management practices in the United States, only around 20 to 30 Mg of agriculture lime is applied each year, making up a fraction of the required recommendation [16]

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Conclusion