Furrow loose and ridge compaction plough layer structure optimizing root morphology of spring maize and improving its water use efficiency

Abstract: To design the construction of the plough layer can be an important approach to solve rainfed farmland problems. In order to investigate the effect of plough layer construction on water use efficiency (WUE) and root morphology of spring maize, four tillage construction modes, including up the loose and down compaction plough layer (ULDC, CK), the furrow loose and ridge compaction plough layer (FLRC), the all loose plough layer (AL) and the all compaction plough layer (AC), were selected to carried out the two years（year of 2015 and 2016）tests at the Fuxin Scientific Observing and Experimental Station of Agro-Environment of China. The results showed that there was a significant influence on the grain yield of spring maize in these four plough layer constructions. In two years of 2015 and 2016, the maize grain yield under the treatment of FLRC was the highest (8 630.47±304.33 and 11 865.41±410.85 kg/hm2 respectively), the treatments of AC was 8 601.47±388.18 and 11 865.41 kg/hm2 respectively, and AL was 7 600.27±756.73 and 10 803.56±410.85 kg/hm2 respectively, whereas the yield under the treatments of CK was lowest (6 436.52±412.46 and 9 140.73±267.83 kg/hm2 respectively). The FLRC treatment raised the yield of spring maize by 18.19% to 34.86% from 2015 to 2016 compared with CK, it was mainly due to an increase in the number of grains per row. After the FLRC treatment, the spring maize biomass (P<0.05) was also enhanced with an the rising rate of 5.18% to 11.30% compared with CK from 2015 to 2016. There was great benefit to the water use of spring maize after the FLRC treatment, with an increment of 1.20% to 5.42% in water consumption, with an increment of 2.74% to 6.23% in biomass WUE and with an increment of 18.23% to 31.49% in yield WUE (P＜0.05) compared with CK in 2015. In addition, these observed results varied between the dry year and wet year. The treatments of FLRC and AC were better suitable for the dry year, while the treatments of FLRC and AL were better suitable for the wet year. In the FLRC treatment, three factors, including the weight density of roots, the length density and the surface area density of roots, can result in the enhancement of the yield of the spring maize during the filling stage. The weight density root was dominated to promote the WUE of biological yield, the WUE of grain yield and the use efficiency of rainfall. The findings demonstrated that the furrow loose and ridge compaction plough layer (FLRC) can served as an efficient soil construction to improve WUE and the root morphology of the cropland, and provide insightful potentials into the dryland farming near the western Liaoning Province in the northeastern of China.