Cover Crops and Corn Residue Removal: Impacts on Soil Hydraulic Properties and Their Relationships with Carbon

Abstract

Large-scale crop residue removal may negatively affect soil water dynamics. Integrating cover crop (CC) with crop residue management can be a strategy to offset potential adverse effects of residue removal. We studied: (i) the impact of corn (Zea mays L.) residue removal (56%) with and without the use of winter rye (Secale cereale L.) CC on soil hydraulic properties, (ii) whether CC would ameliorate residue removal effects on hydraulic properties, and (iii) relationships of hydraulic properties with soil organic C (SOC) and other properties under irrigated no-till continuous corn on a silt loam in south central Nebraska after 5 and 6 yr of management. Cover crops did not affect soil hydraulic properties. However, residue removal reduced cumulative water infiltration by about 45% in one year. Across years, residue removal reduced plant available water (PAW) by 32% and mean weight diameter of water-stable aggregates (MWD) by 23% for the upper 5-cm soil depth. Under no CC, residue removal reduced SOC concentration by 25% in the 0-to 5-cm and by 11% in the 5-to 10-cm depths. Under residue removal, CC increased SOC concentration by 18% in the 0-to 5-cm and by 8% in the 5 to 10-cm depths. Cover crop did not completely offset the residue removal-induced decrease in SOC concentration in the upper 5-cm depth. Plant available water decreased as SOC concentration and MWD decreased. After 6 yr, corn residue removal adversely affected soil hydraulic properties and SOC concentration, but CC was unable to fully offset such adverse impacts. Abbreviations: CC, cover crop; MWD, mean weight diameter of water-stable aggregates, PAW, plant available water, SOC, soil organic C. P roper management of soil and water resources is critical to sustain agricultural production under fluctuating climatic conditions, which include changes in precipitation patterns, heat waves, droughts, and others. In the central Great Plains, management of soil water resources is of special interest because precipitation is often supplemented with irrigation to meet crop production goals (USDA, 2013). Improved agronomic management strategies are needed to address the above concerns (Wienhold et al., 2018). Practices such as CC and crop residue management that maintain or increase surface residue cover can increase precipitation capture, reduce evaporation, and increase water retention capacity. Cover crops can impact soil water management decisions (Unger and Vigil, 1998; Daigh et al., 2014; Basche et al., 2016a). In water-limited regions, CC could reduce PAW needed for main crop production (Nielsen et al., 2016; Alvarez et al., 2017). However, CC may be able to also contribute to water storage by increasing water infiltration, retention, and PAW in the long term. Improved management of CC may ameliorate the negative impacts of precipitation fluctuations (

Preliminary Effects of Crop Residue Management on Soil Quality and Crop Production under Different Soil Management Regimes in Corn-Wheat Rotation Systems

“…The highest value (27%) of this parameter was recorded in NT with full retention of crop residue (NTR 100 ), while the lowest (~15%) values were observed under CT without residue application (CTR 0 ). The present results are in agreement with the findings of the others [70,98]. In the NT, soil layer of 0-10 cm had significantly higher available water content than that of 10-20 cm, whereas, in CT, the differences between two depths were not significant (Tables 5 and 6).…”

Cover crop impacts on soil physical properties: A review

“…For example, CCs may not change water infiltration until other properties, such as aggregate stability and porosity, improve. Indeed, soil pore‐size distribution, which directly affect water transmission characteristics, are slow to change, particularly under low rates of CC biomass production (Sindelar et al., 2019a). Potential factors influencing changes in water infiltration after CC adoption are discussed below.…”

“…A synthesis of global literature on the effects of CCs on soil compaction, aggregation, pore‐size distribution, saturated and unsaturated flow, water retention and available water, thermal processes, and others can be valuable to advance our understanding of CC management impacts on soil physical environment. Some individual studies on CCs reported that CC effects on soil physical properties can be variable depending on soil type, CC species, CC biomass production, tillage and cropping system, and climate (Blanco‐Canqui & Jasa;, 2019; Ruis et al., 2020; Sindelar, Blanco‐Canqui, Virginia, & Ferguson, 2019a, 2019b). Also, an increase in soil organic C (SOC) is often considered to improve soil physical properties, but such correlations across CC studies have not been widely discussed to better understand the mechanisms by which CCs can improve soil physical properties.…”

Do Grass and Legume Cover Crops Improve Soil Properties in the Long Term?

“…Despite the general belief that cover crops (CCs) can improve soil properties and productivity, research data suggest that CC impacts on soil properties, particularly soil physical properties, are inconsistent. Recent studies from different regions reported that CCs can have variable effects on soil physical properties (Barker et al, 2018; Blanco‐Canqui et al, 2017; Dozier et al, 2017; Rorick and Kladivko, 2017; Sindelar et al, 2019). A review of published studies from temperate regions also concluded that CC effects on soil ecosystem services can be variable (Blanco‐Canqui et al, 2015).…”