Study On The Effect Of Biochar On Sloping Land In Black Soil Area

The black soil area in the northeast of China,as the main production area of grain,is of great significance to food security.However,due to the long-term high-intensity utilization of black soil resources,lack of reasonable management mode and the concentration of rain period in the region,the serious soil and water loss phenomenon has led to a huge crisis in the northeast black soil region behind the successive years of corn harvest,which is mainly manifested in the low soil nutrient storage capacity,the thinning of black soil arable layer,soil acidification,the decline of land productivity and the burning of straw resources Cause environmental pollution,etc.Therefore,the improvement of soil quality,the protection of soil and water resources and the effective utilization of straw resources are the key to the sustainable development of northeast black soil area in the future.Biochar,as a kind of environmental friendly soil improver,has become one of the focuses of many scholars at home and abroad.Biochar can exist in the soil for a long time because of its strong stability,and the impact of biochar on the land and crops is a long-term and complex process.However,the current research on biochar is mostly short-term,and there is no discussion on the long-term effect of biochar.Therefore,in 2015,we carried out a study on the application effect of biochar on Hongxing farm in Bei'an City,Heilongjiang Province.According to the application amount of biochar,we set Y0(0 t/hm2)?Y25(25 t/hm2)?Y50(50 t/hm2)?Y75(75 t/hm2)?Y100(100 t/hm2)5 treatments,each treatment repeated twice,and continuously applied for 4 years(2015-2018),observed soil physical and chemical properties,soil and water conservation effect,water saving and yield increasing effect and other indicators,analyzed and discussed the change rule of the above indicators,so as to provide scientific basis for the efficient use of biochar in black soil area.The results show that:(1)With the increase of biochar application amount and application period,soil bulk density decreased,and the larger the cumulative application amount of biochar,the more obvious the trend was;the field water holding rate of Y25 and Y50 treatment increased year by year with the increase of application period,Y75 treatment increased first and then decreased,and the field water holding rate of Y100 treatment decreased year by year With the increase of biochar application,the saturated water content in four years always increased;soil p H value,total organic carbon content and available potassium content increased gradually with the increase of biochar application amount and application period,while the alkaline nitrogen and available phosphorus content increased first and then decreased with the increase of biochar application amount.(2)The annual runoff coefficient and the annual soil erosion amount of four years decreased first and then increased with the increase of carbon application amount,and the flow reduction effect and soil erosion resistance effect of continuous application of 50 t / hm2 biochar for two years were the best;the analysis of typical rainfall flow and sediment production process showed that the application of biochar could delay the flow and sediment production time,and achieve the effect of reducing the flow and sediment production,but when the carbon application amount was too high,the production Flow and sediment yield increased.(3)Biochar can increase the soil water content of 0-60 cm soil layer for four consecutive years,but has little effect on the soil water content of 60-100 cm soil layer.(4)In four years,the plant height,stem diameter and leaf area index of Maize in each growth period increased first and then decreased with the increase of biochar application,and the optimal treatment was Y50,Y50,Y25 and Y25 respectively.In 2018,the plant height,stem diameter and leaf area index of Y100 treatment were lower than those of the control group.(5)The yield and its components of maize increased first and then decreased with the increase of biochar application amount and application period.The optimal treatment in four years was Y50,Y50,Y25,Y25 in 2018,the yield of Y25 treatment was the highest,which was 10350 kg / hm2.The yield of Y100 treatment was 1.1% lower than that of the control group.(6)The water use efficiency of maize increased first and then decreased with the increase of carbon application amount and application period.The optimal treatment for four years was Y50,Y50,Y25 and Y25,respectively.Among them,the water use efficiency of Y50 treatment increased the most in 2015,which was 17.57% higher than that of the control group,while the treatment of Y100 in 2018 was lower than that of the control treatment by 4.1%.