| Biochar is a kind of highly aromatic and insoluble solid material which is produced by the pyrolysis and carbonization of biomass,such as plant and animal manure.Biochar can be stored in the soil for hundreds of thousands of years,and the soil rich in biochar is higher than the soil near the biochar free.Sulfur plays an essential role in crop growth and cell metabolism,It is an important component of plant tissue structure and protein,and other important biochemical reactions such as plant photosynthesis are inseparable from the participation of sulfur.Light sierozem(Loess)widely distributed in the western region of China,with loose structure,barren land,strong water permeability,the porosity is the characteristics of agricultural land as planting crops often yield is very low.However,with the rapid increase of China's population and the increasing demand for food,agricultural land is becoming more and more serious.It is urgent to improve the yield of crops by improving the soil.With the loss of nutrients in cultivated land is becoming more and more prominent,biochar as a new type of environmentally friendly soil amendment has been paid more and more attention.The effects of biochar on the soil physical and chemical properties and the physiological characteristics of the plant were also inadequate.At present,the study on the influence of biochar on soil nutrients is focused on N?P?K and so on,It is urgent to find out the law and mechanism of the effect of biochar on the quality of crops,soil enzymes and the transformation of sulfur in soil and plant availability.In this paper,through cabbage and corn crop cultivation experiments,the amount of exogenous sulfur applied was 0,50,100 mg/kg,and the application rate of dairy manure biochar was 0,0.5,1,2 and 5%.In order to study the effects of biochar on plant growth and development,nutrient quality and sulfur availability.To provide reference basis for the application of biochar in farmland soil.The main results are as following:(1)Biochar affects the growth and development of Chinese cabbage and the availability of sulfur,under the same level of sulfur application,the content of chlorophyll increased first and then decreased with the increasing amount of biochar,and don't reached a significant difference level(P < 0.05).When the amount of biochar was 5%,the chlorophyll content of leaves was the lowest;The content of soluble sugar increased with the increasing amount of biochar,and reached a significant difference level(P < 0.05).In the 5% biochar treatment,the soluble sugar content of Chinese cabbage leaves increased by 126%,196% and 106%,compared with the control group,respectively.The soluble sugar content had no significant relationship with the change of biochar and sulfur;The soil pH increased with biochar application,When the biomass carbon content was 5%,it increased by 7.6%,9.5% and 5%,compared with the control group,respectively;Soil catalase,urease and invertase did not change significantly with the application of biochar(P < 0.05).The enzyme activity of three kinds of soil showed different degrees of decline when the biomass was 5%;The application of dairy manure biochar could increase the absorption of sulfur in the leaves of Chinese cabbage,which was the most significant under high sulfur treatment,There was a significant correlation between the concentration of sulfur and total sulfur in the leaves of Chinese Cabbage(P < 0.05).The soil total sulfur and inorganic sulfur decreased with the increase of biochar treatment;The effects of biochar on the accumulation of sulfur in Pakchoi were mainly attributed to the improvement of soil physical and chemical properties,the availability of soil nutrients,and the enhancement of soil microbial abundance and enzyme activity.(2)Biochar affects the growth and development of corn and the availability of sulfur.With the increase in the amount of biochar,the chlorophyll content of corn leaves increased first and then decreased,and reached a significant difference.When the application amount was 2%,the chlorophyll content of corn leaves was the highest;The content of soluble sugar increased with the increasing amount of biochar,and reached a significant difference level(P< 0.05).The soluble sugar content was the highest under the 5% treatment level;The soluble protein content increased first and then decreased with the increase of biochar,When the dosage was 2%,the content of soluble protein in leaves was the highest,which was increased by 36%,35% and 34%,respectively;When the biochar was 2%,the plant height of corn was the highest,and the plant height of corn in the application of reached 128.8 cm,142.2 cm and132.6 cm,respectively,and reached a significant difference level(P < 0.05).When the applied amount of dairy manure biochar was 5%,the plant height of corn was the lowest;The fresh weight and dry weight of corn showed a trend of increasing first and then decreasing with the increase of biomass carbon application,When the amount of biochar is 2%,the fresh weight and dry weight are the heaviest,and fresh weight reached 941.2 g,1035.7 g and 990.9 g,dry weight was 364.1 g,419.2 g and 380.1 g;The soil pH increased with the increase of the amount of biochar;Three kinds of soil enzyme activity increased with the increase of biochar,and then decreased.When the application amount was 2%,the activity of the enzyme was the strongest in the three kinds of soil,the content of sulfur in corn leaves and roots was the highest and the sulfur content in corn leaves increased by 92%,61% and 73%,respectively,the sulfur content in corn roots increased by 24%,29% and 34%,respectively;When the amount of the same biochar was applied,the total sulfur content in soil showed the trend of low sulfur < middle sulfur < high sulfur and Rhizosphere soil extraction sulfuric acid extraction < phosphoric acid extraction < hydrochloric acid extraction;At the same treatment level,the sulfur content of the three extracts decreased with the increasing concentration ofbiochar,After the application of biochar reached 2%,the concentration of sulfur was increased. |
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