Impact of cover crop on corn–soybean productivity and soil water dynamics under different seasonal rainfall patterns

  • Authors: Yang, Wei; Feng, Gary; Read, John J.; Ouyang, Ying; Han, Jianjun; Li, Pinfang
  • Publication Year: 2020
  • Publication Series: Scientific Journal (JRNL)
  • Source: Agronomy Journal
  • DOI: 10.1002/agj2.20110

Abstract

The effect of cover crop (CC) on soil water balance and agricultural production is
closely related to rainfall amount and distribution in rainfed cropping systems. This
study used the root zone water quality model, RZWQM2, calibrated and validated
with 4-yr field measurements to predict the effect of planting a winter wheat (Triticum
aestivum L.) CC in a no-till rainfed corn (Zea mays L.)–soybean (Glycine max L.)
rotation on soil water balance, crop yield, and grain water-use efficiency (WUE) in
northeast Mississippi. Seasonal rainfall for 80 consecutive years (1938–2017) was
classified as ‘wet,’ ‘normal,’ and ‘dry’ years using frequency analysis, and the data
sets matched chronologically to wheat, corn, and soybean growth periods were used
as an input parameter in RZWQM2 simulations. During autumn and spring (early
October to early April), the CC reduced deep drainage by 69 (11%), 53 (15%), and
51 mm (21%) in wet, normal, and dry years, respectively. Averaged across 40 yr,
the CC decreased surface evaporation by 64 (32%) and 38 mm (24%) for corn and
soybean growth periods, respectively. Wheat CC also improved soil water storage
in early crop growth period during April–June in any of the three rainfall patterns.
Regardless of rainfall patterns, the increase in WUE can be attributed to a decrease
in evapotranspiration during cash crop period without sacrificing cash crop yield in
the CC system. Introducing CC into cropping systems is beneficial to reduce annual
deep drainage and evaporation while maintaining higher crop yields under different
rainfall patterns.

  • Citation: Yang, Wei; Feng, Gary; Read, John J.; Ouyang, Ying; Han, Jianjun; Li, Pinfang. 2020. Impact of cover crop on corn–soybean productivity and soil water dynamics under different seasonal rainfall patterns. Agronomy Journal. 112(2): 1201-1215. https://doi.org/10.1002/agj2.20110.
  • Keywords: cover crop, evapotranspiration, RZWQM2, water-use efficiency
  • Posted Date: July 27, 2020
  • Modified Date: August 5, 2020
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