Mechanism And Effects Of HA Compound Fertilizer On The Yield And Nutrient Utilization Of Red Pepper

In this thesis, the study was conducted to determine the effects of humic acid (HA) compound fertilizer on soil fertility, nutrient release of soil, nutrient utilization and the growth of red pepper (Capsicum frutescens L.). In addition, the physiological mechanism of HA compound fertilizer promoting the growth of red pepper was researched, which included stomatal diffuse resistance, transpiration rate, nitrate reductase (NR) activity, superoxide dismutase (SOD) activity, peroxidase (POD) activity and chlorophyll contents. The results indicated: â‘ A compound fertilizer not only improved the yield by 8.1%-23.5% and contents of dry matter of red pepper obviously, but also had clear advantages in hastening maturity of fruits and preventing premature senescence of plants. ?Among the series of fertilizer treatments, the physiological effects were the best generally and the yield of red pepper was the highest applied by HAZn. For this reason, HAZn was considered the best treatment for the growth of red pepper. ?The effects of HA compound fertilizer on the growth of red pepper were realized by HA regulating a series of physiology activity of red pepper, such as improving activity of NR, SOD and POD, increasing transpiration rate and decreasing stomatal diffuse resistance, raising chlorophyll contents of red pepper leaves and so on. Among of them, SOD activity was closely related with yield of red pepper(r0.9473*).? HA compound fertilizer could promot N,P,K,Zn,Fe uptake and utilization by red pepper, so that increased fertilizer apparent recovery and agronomic efficiency. But the effects were more and more lower along with increase of fertilizer rate. ?zinc and iron can not be applied at the same time because there is negative interaction between them. ?The relationship between applied fertilizer rate and yield of red pepper was described with quadratic curve regression model. The R value of HA compound fertilizer and inorganic 59 fertilizer was 0.9813 and 0.9713? respectively. According to the equation, the highest rate of HA compound fertilizer is 3.29glpot, accordingly, the highest yield of red pepper is 165.22glpot. The yield of red pepper was higher by 10.00% than that applied by equal nutrients of inorganic fertilizer. ?Through applying HA compound fertilizer, the contents of organic material ,available N and available P were increased than that applied by equal nutrients of inorganic fertilizer. Total humus, humic acid and HAIFA were all raised. The quality of soil humus was also impoved. ?Compared to inorganic fertilizer and HA compost fertilizer, the total quantity of released N treated by HA compound fertilizer was decreased by 58.34% and 48.78%, respectively. This results indicated that N of HA compound fertilizer could be released slowly. In addition, HA could improve activity of P in soil.