The Combined Influence of Cover Crops and Manure on Maize and Soybean Yield in a Kentucky Silt Loam Soil

Maheteme Gebremedhin,Mark Coyne,Sait Sarr,Karamat R Sistani,Jason Simmons

doi:10.3390/su11216058

Abstract

Management that degrades soil can be one of the main causes of low agricultural productivity and environmental problems in many agricultural regions. There is renewed interest in soil conservation practices to promote sustainable agriculture by improving soil quality and productivity. In this study, the short-term on-farm benefits of cover crops and manure on crop yield and biomass were examined during two consecutive growing seasons. The experiment was conducted at a small-producer farm in Logan County, Kentucky, USA. Soybean (Glycine max L.) and maize (Zea mays L.) were used as summer annual rotation crops in no-tilled soils. A cover crop mix of cereal rye (Secale cereale L.), Austrian winter pea (Pisum sativum L.), and crimson clover (Trifolium incarnatum L.) was planted after the main crop was harvested each year. Aboveground biomass of the soybean and maize were assessed, and yield was estimated from hand-harvested plants. In the first year of the study (2016), there were apparent but not significant beneficial effects of animal manure and cover crops on soybean yield, but not on biomass. The biomass and maize grain yield in the second year (2017) were detectable, significant, and increased as a result of the cover crops and manure application (p < 0.05). While beneficial effects of combining cover crops and manure may not be obvious in the first year of a rotation, they can be apparent in subsequent years. However, longer-term observation and measurement are necessary to better quantify the relationship between sustainable conservation practices and productivity.

Highlights

IntroductionSustainability, and productivity are a global concern for food security and environmental quality [1,2]
Soil management, sustainability, and productivity are a global concern for food security and environmental quality [1,2]
These results suggest that cover crops may have a significant, if contradictory, influence on crop yield

Summary

Introduction

Sustainability, and productivity are a global concern for food security and environmental quality [1,2]. Agricultural intensification has caused soil compaction, organic carbon loss, increased evaporation rates, excessive nutrient runoff, and biodiversity loss, all negatively affecting agricultural soil productivity, sustainability, and resilience [2]. Soil conservation practices such as cover cropping and amendment with animal manure may mitigate effects of soil degradation and hold the promise of increasing soil quality, crop productivity, and decreasing soil degradation [2,3]. In a crimped and rolled system, for example, cover crop residues (i.e., winter rye [Secale spp.]) can inhibit early season weed germination and create a path for the subsequent grain crop to outgrow growth- and yield-limiting weeds [5,6] before the rye is decomposed and mixes with the underlying soil. Adverse effects of cover crops, which may inhibit their adoption, include N immobilization [14], competition for nutrients and water [15], and promotion of pest animals (e.g., voles [Microtus ochragaster]) [16]

Methods

Results

Conclusion