Cultivation models and mulching strategies to improve root-bleeding sap, nutrients uptake and wheat production in semi-arid regions

Abstract

The application of mulching materials has significantly improved the production of wheat in semi-arid regions. However, various mulching applications under different tillage practices, whether it can improve the root growth, spatial distribution of root, nutrients uptake and grain yield of wheat is not clear. Therefore, a two years field study was carried out during 2016–17 and 2017–18 to evaluate root growth, nutrients uptake, and wheat production under six treatments: CT: conventional planting; SM: wheat stalk mulching; FM: plastic mulching; RT: without plastic mulching with furrow and ridge planting; RP: plastic mulching with furrow and ridge planting; RPS: plastic mulching on ridges and stalk mulching on furrows. Under the RPS treatment, root biomass, soil moisture, soil enzymatic activity, and microbial abundance can be significantly improved, thus promoting root growth, nutrient absorption, and wheat production. The RPS treatment significantly improved the rooting system in the upper soil profile of 50 cm, which helped increase the yield of wheat. At various wheat growth stages, the RPS and RT treatment at the depth of 10–50 cm significantly increased root bleeding saps, and RLD, and reached up to the highest value at 125 DAP. However, there were no differences in RLD between the six different treatment methods in deeper soil profiles below 60 cm. In addition, during 2016–17 and 2017–18, the NH4+ and NO3- delivery rates under the RPS were significantly higher than that of FM and RT, while the delivery rates of NH4+ and NO3- under the RP treatment were maximum compared with FM practice. Under the RPS and RT treatments, the Fe, Ca, P, Zn, K, and Mg delivery rates were significantly maximum. In summary, RPS farming practices have been great potential to improve the rhizosphere environment, root biomass, and wheat yield in semi-arid regions.