Mechanical and ecological tillage pattern improving soil quality and crop yields

Abstract: Tillage was the key factor affecting soil quality, and plowing, rotary tillage and subsoiling etc. were the important links of tillage pattern. Years of plowing, trying to make the soil crushing and creating a good growth environment were the essence of traditional farming in China. But excessive tillage caused the damage to the vegetation, made the soil lose protection, caused soil erosion, dust wreaking havoc and fertility decline in the end. However, long-term no tillage was also inconducive to the sustainable high yield of crops. In order to solve this problem, through comprehensive consideration, the advantages of different tillage patterns were took and combined reasonably. Then a rotational period of mechanical and ecological tillage pattern was established in wheat/corn double-cropping system and compared with the patterns of years of plowing and years of no tillage. The mechanical and ecological tillage pattern was set as Treatment W, the years of plowing pattern was Treatment F, and the years of no tillage pattern was Treatment N. The rotational period was set to be 5 years. For Treatment W, different agricultural machines were combined suitably for moderate tillage on soil in the 5 years. In the first year, the soil was ploughed with the splintery straw mulch on the soil after harvesting corn, and no tillage the next year; in the third and the fourth year subsoil interleaved, and in the last year no tillage as well. For Treatment F the soil was ploughed every year after harvesting corn and no tillage for Treatment N. In order to study the effects of different patterns on soil and yield, the soils of 0-10, >10-20, >20-30 cm layer were collected and tested for soil organic content, moisture content and bulk density, and yields of wheat and corn were recorded as well every year in the period for all treatments. Then the results were compared. The comparison results showed as follows: in the period of five-year test, Treatment W effectively improved soil organic content at all 3 layers, and the largest improvement was 0.2% at 0-10 cm soil layer; Treatment N also significantly improved soil organic content at 0-10 cm soil layer at the first 3 years, but reduced at the last 2 years; however, soil organic content was reduced for Treatment F at 0-10 cm layer, yet that at >20-30 cm soil layer was significantly improved at the first 3 years, and then reduced at the last 2 years. The soil moisture contents from the highest to the lowest were Treatment W, Treatment N and Treatment F, and the difference between Treatment W and the two other treatments was more significant (P<0.05) with the increasing of the year. At 0-10 cm soil layer, the soil bulk densities of Treatment W and N were significantly lower than Treatment F at 5% level. The yields of Treatment W and N were significantly higher than Treatment F, and the order from the highest to the lowest was Treatment W, Treatment N and Treatment F; the difference was most significant in 2014, wheat yields of Treatment W was 30.8% higher than Treatment F and 22.5% than Treatment N, and yields of corn was 28.4% higher than Treatment F and 20.9% than Treatment N.