Study On The Improvement Of Tea Plantation Acidified Soil By Biochar

Camellia sinensis(l.o.Ktze.)is a perennial evergreen woody plant native to China.Tea tree likes acid,but too high acidity in soil will affect the physical and chemical properties of soil,and adversely affect the yield and quality of tea,so soil acidity needs to be controlled.The acid-base buffer capacity is usually used as an index to express the acid-base buffer capacity of soil.The larger the acid-base buffer capacity,the stronger the buffer capacity of the soil.Biochar is a kind of solid material containing black carbon produced by high temperature pyrolysis of agricultural and forestry wastes under anaerobic conditions.Biochar is generally alkaline,and studies have shown that the application of biochar can improve soil fertility,reduce soil acidity,and improve soil acid-base buffering performance.In this experiment,the acid-base buffering performance and physicochemical properties of tea garden soil planted with Yinghong No.9 tea tree in different years were studied.The results showed that the p H of the soil decreased with the increase of the growing years.In addition to the young tea growing area soil of 2 years,the organic matter,cation exchange capacity,exchangeable base ions and clay content in the soil of other tea growing years all decreased with the growth of tea growing time.The acid-base buffer capacity of soil decreased with the increase of tea planting years.By analyzing the biochemical components of spring tea in soil with different planting years,it was found that tea polyphenols and water extracts in tea increased with the increase of planting years.There was no significant difference in the content of free amino acids.The content of soluble sugar decreased with the growing years.The effect of biochar on soil acidification improvement was investigated through a 45-day laboratory culture experiment.The results showed that soil physical and chemical properties were improved,and soil acid-base buffer capacity increased with the increase of biochar concentration.Compared with the blank treatment,the acid-base buffer capacity of soil was increased by 16.59%,22.12%,31.24%and 50.98%respectively after the treatment with biochar of 1%,2%,5%and 8%concentrations.In this experiment,the outdoor potted experiment of biochar was carried out,and the potted tea tree grew well.After one year of potting,treatment with 1%,2%,5%and 8%biochar compared to the control,there was no significant difference in tea yield,plant height and shoot length.With 5%and 8%biochar added,banners increased by 23.17%and 22.57%,respectively.The main stem of tea tree was increased by 5.12%with 5%biochar.When treated with 5%biochar,the growth of new shoots increased by 22.10%compared with the control.The 8%biochar treatment increased the leaf area by 1.62%compared to the control.Through the influence of biochar on the growth index of tea tree,it can be seen that the biochar treatment with 5%concentration has a significant positive effect on the growth of potted tea tree.Compared with the soil before the experiment,the p H of the soil increased as a whole after potting and increased with the increase of biochar concentration.Compared with the control group,soil organic matter treated by 1%,2%,5%and 8%increased by 38.60%,57.89%,74.56%and 91.23%,respectively.Biochar increased the content of exchangeable base ions in soil,decreased the content of exchangeable acids,and the base saturation increased with the increase of biochar treatment concentration.The acid-base buffer curves before and after the potted experiment were of"S"type,and the curve of high concentration biochar treated in the sudden range of ph4.0-6.0 was gentler than that of low concentration.Compared with the blank treatment,the acid-base buffer capacity of soil increased gradually with the increase of the amount of biochar.The acid-base buffer capacity of soil increased by 224.23%and 206.89%with the addition of 5%and 8%weight proportion of biochar,respectively.The results of 5%concentration treatment were the most significant.In this study,biochar field experiments were conducted on Yinghong No.9 tea plantation.After 16 months of experiments,the results showed that the biochar treatment at2 kg/m~2 could increase the contents of water extract,amino acid,soluble sugar,tea polyphenol and caffeine in tea leaves of young tea area,and it might decrease with the decrease of biochar concentration.Biochar treatment can significantly increase the content of tea polyphenols in tea in adult tea areas.The results of field experiments show that for the soil of young tea area,biochar can increase the p H value,organic matter,hydrolytic nitrogen and available phosphorus in soil,and can also significantly increase the available potassium content of soil.In terms of the impact on the environment and ecology,biochar can increase the content of cation exchange capacity,exchangeable magnesium,exchangeable potassium and exchangeable sodium in the young tea area,significantly increase the exchangeable calcium content of the soil,and significantly reduce the content of exchangeable acid in the soil.In addition to the effect on young tea growing areas,biochar can also effectively improve soil organic matter and significantly reduce exchangeable acids in the soil of adult tea growing areas.In summary,the acid-base buffer capacity of Yinghong No.9 tea garden soil decreased with the increase of tea planting years.The application of biochar is beneficial to the growth and development of tea trees,improves the quality of tea leaves,improves the acid-base buffering performance of soil,and improves the soil acidification in tea plantations.