| Western Liaoning is one of the important corn producing areas in Liaoning Province.The average annual rainfall in this area is 350-500mm,which is concentrated in June,July and August.The soil layer is shallow,the plough bottom is thick,the fertility is low,and the ability of water storage and moisture preservation is poor.In winter and spring,there is little precipitation,strong wind and frequent drought in spring,which seriously affects the corn sowing and seedling growth,which is the biggest limiting factor of agricultural production in this area.In view of the existing problems in this area,many researches have been carried out by predecessors,such as mulching,straw returning to the field and farming methods,etc.;however,till now,there is no effective farming mode to solve the practical problems,such as low capacity of soil water storage and moisture conservation,spring drought of soil,equal rain sowing and so on.In this paper,based on the field plot experiment,taking the traditional rotary tillage model as the contrast,the effects of five tillage models on the water temporal and spatial distribution of 0-80cm profile,the physical and chemical properties of the plough layer,the growth of corn,the distribution of root system and yield were studied in the cinnamon soil area of western Liaoning Province.The effects on the water storage in rainy season,the water use efficiency of water conservation in spring and the economic benefits were emphatically discussed.To optimize and select the cultivation mode that can improve the water storage of soil in rainy season and spring sowing,and is suitable for the growth and development of corn root system.In order to provide theoretical basis and technical support for the construction of suitable production and Cultivation Mode in the cinnamon soil area of western Liaoning Province.The results are as follows:1.Compared with rotary tillage（CK）,the soil bulk density of each tillage method in 10-20cm layer was reduced.The soil compactness of different tillage methods at 15-25cm was less than that of rotary tillage.2.In terms of time,from pre sowing to jointing（April 16 to June 6）in 2018,no till straw mulching provided a higher soil moisture content,ensured the emergence of corn,and strengthened the soil water supply at seedling and jointing stages.Compared with other tillage methods,the integrated model significantly increased the soil water content of 0-80cm,especially in the 20-40cm layer.Before spring sowing in 2019（April 12）,the integrated soil moisture content model of 0-10cm and 10-20cm（13.15%,14.12%）was higher than that of no tillage straw mulch（11.30%-13.04%）and other tillage methods.Even in the absence of rainfall,the soil moisture content of the integrated model could meet the requirements of maize seedling emergence.3.In space,there are obvious differences in the depth of precipitation energy infiltration in the short-term of each farming method in rainy season,which are:rotary tillage 0-20cm,deep loosening 30-40cm,ploughing 20-30cm,no tillage straw covering 20-30cm,integrated mode30-40cm.During the drought,the soil moisture content of rotary tillage and subsoiling at the 0-80cm layer was at a lower level,the soil moisture content of ploughing was slightly higher than that of subsoiling,the soil moisture content of no tillage straw mulching at the 0-80cm layer was slightly higher than that of no tillage straw mulching at the 0-80cm layer,especially at the20-40cm layer.4.Compared with no tillage straw mulching,the integrated model accepted more rainfall from rainy season to autumn harvest stage,and the soil water storage increased by 8.70mm-15.30mm,which provided more soil water for corn growth in the middle and later stages.Before the spring sowing in 2019（April 12）,the integrated model can better conserve soil water,and its soil water storage is 12.66mm higher than that of no till straw mulching.5.The available NPK of no tillage straw mulching accumulated in the surface layer,and the deep loosening was beneficial to the improvement of the available NPK in the lower layer.6.In rotary tillage,it is not conducive to the growth and development of corn to sow ahead of time or delay sowing after rain.No till straw mulching had the slowest growth in the early stage of corn growth.In the middle and later stage of maize growth（after jointing stage）,the growth trend of no till straw mulching and integration mode began to rise in the middle and later stage,and finally exceeded that of rotary tillage and ploughing.Compared with rotary tillage,deep loosening is beneficial to increase the amount of root system in the subsoil.7.In 2018 and 2019,the output of rotary cultivation is the lowest,and the output of integrated mode is the highest.Compared with CK,the integrated mode will increase production by 18.93%in 2018 and 31.75%in 2019.The water use efficiency of integrated mode is significantly higher than that of other tillage methods,and it is the highest in 2018 and 2019,respectively,32.49kg·hm2·mm-1 and 30.28kg·hm2·mm-1.8.In 2018 and 2019,the profit of integrated mode was significantly higher than that of other farming methods,with an increase of 3321.16 yuan/hm2 and 7074.97 yuan/hm2,respectively.According to the two-year data,the economic benefit of the integrated model is the best,which can increase the income of local farmers.To sum up,in view of the limiting factors of high-yield corn in western Liaoning,compared with other farming methods,the integrated model has better improved the soil moisture in spring and preserved the water storage of the lower soil,has good soil water supply capacity,appropriately reduced the bulk density and compactness of the soil,has a good growth of corn,promoted the growth of root system,and has achieved stable in different years High yield and increased water use efficiency and economic benefits.The integrated model is a new high and stable yield farming method which is worth popularizing in the dry farmland in the west of Liaoning Province. |
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