| The albic soil is an"acid,sticky and heavy"low productive soil mostly distributed in major grain producing areas,e.g.,Heilongjiang,Jilin and etc.Wide distribution,large area,bad physical structure,and poor nutrition are the major obstacle factors for the albic soil.How to improve the obstacle factors based on relevant physical and chemical properties is the key to advance the comprehensive productivity of albic soil.In this study,a field experiment was carried out with biochar soil conditioner made from a mixture of fermented livestock and poultry manure and corn stalk biochar as the material.In the experiment,for straw returning to soil,straw carbonization was combined with straw transformation through feeding livestock,and different dosages(0t·hm-2,1.5t·hm-2,4.5t·hm-2,7.5t·hm-2,15t·hm-2)of biochar soil ameliorator were analyzed for the influence on basic physical and chemical properties of albic soil,as well as its microstructure,so as to provide technical support for the improvement of albic soil.The main conclusions are as follows:As the dosage of biochar soil conditioner was increased,the soil bulk density and specific gravity were decreased significantly.In 2019,15t·hm-2of biochar soil conditioner achieved the best effect in 0-20cm and 20-40cm soil layer,with soil bulk density and specific gravity decreased by 13.2%and 1.90%respectively in 0-20cm,with soil bulk density and specific gravity decreased by 10.9%and 1.54%respectively in 20-40cm.With the increase of biochar soil conditioner dosage,the soil p H value,organic matter,total nitrogen,total phosphorus,alkali-hydrolysable nitrogen,as well as rapidly available phosphorus and available potassium,showed an obvious increasing trend.In 2019,15t·hm-2of biochar soil conditioner achieved the best effect in 0-20cm soil layer.The soil p H value,organic matter,total nitrogen,total phosphorus,alkali-hydrolysable nitrogen,rapidly available phosphorus,and rapidly available phosphorus potassium were increased by 7.87%,15.0%,12.8%,7.75%,36.0%,52.5%and 57.9%respectively,with the soil p H value,organic matter,total nitrogen,total phosphorus,alkali-hydrolysable nitrogen,rapidly available phosphorus,and rapidly available phosphorus potassium were increased by 7.77%?9.79%?8.39%?5.61%?22.2%?38.4%and 46.0%respectively in 20-40cm.Under scanning electron microscope,the soil microporosity showed an obvious increasing trend.Soil microporosity showed an obvious increasing trend based on scanning electron microscopy.In 2020,application of 15t·hm-2biochar in 0-20cm and 20-40cm soil layers had the best effect,and soil microporosity increased by 217.6%.With the increase of biochar content,the pore size distribution and porosity distribution of the inactive pores with pore size less than 2?m decreased by 0.171%-6.59%and 4.76%-49.9%,respectively.The pore size distribution and porosity distribution of capillary pores with pore size 2-20?m increase by 0.125%-11.1%and5.29%-6.29%,respectively.The pore size distribution and porosity distribution of aerated pores with pore size larger than 20?m increase by 7.77%-132.6%and 2.06%-11.5%,respectively.According to the results of pore size distribution of the three kinds of pores,15t·hm-2biochar has the best improvement effect on pore size distribution and porosity distribution in 0-20cm and 20-40cm soil layers.Relevant data of the two consecutive years showed that the biochar soil conditioner improved the soil p H,organic matter,total nitrogen,total phosphorus,alkali-hydrolysable nitrogen,rapidly available phosphorus,and rapidly available potassium and reduced the soil bulk density significantly.At the same time,it optimized the soil structure,reduced the inactive pores,increased the capillary pores,and aerated pores,and thus,the poor soil aeration,permeability and tillability were alleviated.In this experiment,15t·hm-2of biochar soil conditioner achieved the best effect for improving physicochemical properties and microstructure of the soil. |
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