The Role of Cover Crop Types and Residue Incorporation in Improving Soil Chemical Properties

Rimsha Khan,Farhat Abbas,Bishnu Acharya,Helen Carolyn Peach Brown,Qamar U Zaman,Aitazaz A Farooque,Andrew Mckenzie-Gopsill

doi:10.3390/agronomy11102091

Abstract

Soil chemical properties can be improved by incorporating crop residues in soil and letting it decompose. This study explored the use of incorporating residues of cover crops for improvements in soil chemical properties including soil organic matter (SOM), soil pH, and the selected soil macro- and micronutrients in greenhouse and field trials. Factors of interest included (i) cover crops and their combinations and (ii) methods of crop termination and incorporation in soil (disc, mow + disc, glyphosate, roller crimper). The greenhouse trial showed up to a 20% higher amount of SOM accumulated in soils incorporated with crop residues. Buckwheat (3.12%) and phacelia (3.12%) produced significantly different and larger SOM than that of the control treatment that received no crop residues (p ≤ 0.05). The soil pH of the brown mustard treatment was also significantly affected by the experimental treatments (p ≤ 0.05). The incorporation of crop residues did not affect soil phosphorous (P) or potassium (K) concentrations, except for brown mustard, with significantly higher values of P and K than the control treatment. Calcium (Ca) was significantly higher in the soil of phacelia + pea treatment (p ≤ 0.05). Buckwheat + pea produced a higher concentration of Ca (1028 mg/kg) followed by buckwheat alone (1006 mg/kg). Analysis of variance (ANOVA) calculated on the results of the field trial showed that the mix treatment that had a mixture of four cover crops significantly increased the SOM content. Buckwheat produced the highest (2.95%) SOM, then brown mustard and timothy. This study concludes that, irrespective of the tillage incorporation methods, the residues from cover crops are a potential source of improvement in soil health, and this practice may promote sustainable agriculture in conditions similar to those in this study.

Highlights

Cover crops form a vital bioresource that contributes to improving soil health
The termination and incorporation of cover crops into the soil is another method of promoting microorganism activities for the increased decomposition of crop residues, increasing soil organic matter (SOM) and soil fertility [7]
Cover crop treatments significantly influenced SOM in greenhouse and field trials. These findings are in concurrence with the literature, which indicates that crop residue incorporation is the primary method for improving SOM

Summary

Introduction

Cover crops form a vital bioresource that contributes to improving soil health. Soil chemical properties including organic matter (SOM), soil pH, and soil macro- and micronutrients contribute to soil health. A potential strategy to address soil health issues is improving soil chemical properties through planting cover crops with regular field crops [5]. Cover crops reduce nutrient loss and improve soil conditions. They offer an excellent opportunity to increase the diversity of crop rotation between the cultivation of major crops [4,5]. The termination and incorporation of cover crops into the soil is another method of promoting microorganism activities for the increased decomposition of crop residues, increasing SOM and soil fertility [7]

Methods

Discussion

Conclusion