Tillage And Fertilizer Effects On Soil Physicochemical Properties Of Black Soil

In this research, seven treatments, routine rotary tillage, no tillage, corn stubble mulching, deep sub-soiling, no tillage plus manure, residue mulching plus manure and deep sub-soiling plus manure, in which all treatments used equal rate of nitrogen, phosphorus and potassium fertilizers, were set to study the changes of physical and chemical properties of soil and suitable tillage methods under different tillage methods and fertilizer application.The results showed that the tillage methods were the most influencing factor on the physical and chemical properties of soil. Soil moisture of the treatment with residue mulching was relatively higher than other treatment during the growing season of maize. In prophase and metaphase of growing season of maize, this treatment kept moisture notably higher. The treatment with residue mulching remarkably reduced difference of temperature between upperlayer and underlayer in soil. However, residue mulching on the soil's surface prevented sunlight emission from the sun so the soil surface temperature decreased and the rate of emergence decreased subsequently. The bulk density of soil of the treatment with no tillage plus stubble mulching was higher than that of other treatments during the whole growing season. Rotary tillage decreased bulk density during the prophase of routine treatment which increased with the growth of crops.After harvest, the bulk density had no significant difference for all treatmnets. The field water capacity (FWC) of the seven treatments increased vis-à-vis the routine treatment after the middle growing season of maize. Application of manure increased the FWC the most in the no-tillage plus stubble mulching treatment. The increase in water-stable aggregate followed the order: no-tillage plus stubble mulching > no-tillage plus manure.Tillage had some effect on soil chemical characteristics and soil enzymes during the whole growing season of maize. The available nitrogen (AN) changed a lot during the growing season of corn. Soil AN decreased after the growing season for the routine treatment compared to an increase in AN for the other treatments. Residue mulching increased the AN significantly than the other treatments with the highest AN level for the residue mulching treatment followed by the no-tillage plus stubble mulching.The labile phosphorus (LP) for all treatments followed the rising-falling tendency. Residue mulching treatment and no tillage with stubble remarkably increased the labile phosphorus. In the heavy rainfall season, labile potassium of residue mulching treatment was remarkably higher than that of routine treatment. In the light rainfall season, soil labile K had no significant difference for all treatments. After the maturity of corn, LP had little change with a slightly higher content for the deep subsoiling. The soil pH of residue mulching treatment was remarkably lower than that of other treatments. Application of manure could efficiently increase the soil organic matter.Throughout the maize growing period, soil urease activity had a smoothly increasing trend, but the soil urease activity of no-tillage plus stubble mulching remained at a relatively low level. Soil urease activity of residue mulching treatment was relatively lower at the initial stage but increased rapidely since then. For the manure treatments, the soil urease activity of deep subsoiling plus manure of cow was the highest vis-à-vis the lowest soil urease activity of no-tillage plus stubble mulching treatment. The activity of catalase at the former growing phase of corn for all treatments had no significant difference. At the harvest, soil activity of catalase for the residue mulching was slightly lower than that of the other treatments.In summary, residue mulching was better in amelioration of soil physical and chemical characteristics, but its yield was relatively lower, so its economical benefit was lower. The yield of no-tillage with stubble mulching treatment was equivalent to that of routine treatment, but the latter reduced the mechanical and manpower expenditure, so it had a higher economical benefit, in addition, it can ameliorate the soil physical and chemical characteristics. Application of manure improved the soil physical and chemical characteristics but increased the expenditure, so its economical benefits were not distinct. The tillage method suitable for Shuangcheng County was no-tillage plus stubble mulching.