The Study Of Biochar On Improving The Quality Of Ningxia Low-quality Soil

In recent years, biochar as a kind of environmentally friendly materials shows great potential in terms of soil amelioratioa The study, which based on the light sierozem with the problem of low nutrients content and poor water-retaining property distributed inNingxia Hui Autonomous Region, mainly focuses on the biochar’s agricultural benefits. To seek a better way to amend the fertility of light sierozem, peanut hull was chosen as the raw material to produce peanut hull biochar (BC). Besides, a biochar-based amendment (AD) was made of the biochar which mixed with a certain proportion of chemical fertilizer. The study used two seasons pot experiment and a field experiment to figure out the effect of BC and AD on crop growth and nutrient utilization efficiency. In the pot experiment, BC and AD were added into the soil at the rates of 0%,1.5%,3% and 5%(w/w) respectively to investigate their effects on the growth of the Brassica chinensis and Brassica napus L.in the first season and that of Lactuca saliva var longifoliaf. Lam and Chrysanthemum comnarium in the second season. At the same time, the principal component analysis was used for studying the internal factors of crop growth. In addition, the manurial effect of BC and AD was evaluated. In the field experiment, BC and AD were added into at the rate of 0% and 1.5%to investigate their effects on the growth of Citrullus lanatus and Zea mays L. The main conclusions are as follows: (1) The pot experiment indicates that BC can significantly increase the biomass of Chinese cabbage by 131%～265%, while it have no effect on the growth of rape, lettuce and crowndaisy chrysanthemum, even retards the crop growth at 5%addition volume. Unlike BC, AD, at the low addition volume (1.5% and 3%), can significantly increase the biomass of Chinese cabbage, rape, lettuce and crowndaisy chrysanthemum by 276%～342%,106%～140%,16%～24% and 14%-26% respectively. This shows the effect of AD on crop yield is better than that of BC on crop yeild. The main factors for crop growth are the content of TN, TP and available. phosphorus in the soil through principal component analysis.(2) BC and AD have different effect on the soil pH and nitrogen and phosphorus nutrient content In addition to 3%BC and 1.5%AD in the lettuce soil, BC and AD have no effect on the pH in all the rhizosphere soil. The effect of BC on nitrogen and phosphorus nutrient changes among various vegetation types and crop absorption characteristics. While AD can significantly increase the nitrogen and phosphorus nutrient in the soil.(3) The results show that BC significantly promotes the nitrogen use efficiency of Chinese cabbage, rape and crowndaisy chrysanthemum, which respectively increases by 163%～250%,33% and 29%～43%. AD only increases the the nitrogen use efficiency of Chinese cabbage by 88%-396%, while having no effect other crops. The effect of BC and AD on the phosphorus use efficiency differs from that of on the nitrogen use efficiency. BC has no effect on the nitrogen use efficiency of all the crops, while AD significantly increases that of the Chinese cabbage and rape. It indicates that BC can improve the nitrogen use efficiency in the soil and reduce crop demand for nitrogen fertilizer on the premise of maintaining crop growth. AD can not only promote the crop yield, but also improve phosphorus use efficiency to reduce the crop demand for phosphate fertilizer.(4) The field experiment shows that BC and AD have different effects on corn and watermelon.AD significantly increases the per mu yield, the grain yield and ear yield of corn, while reduces the watermelon fruit weight At the same time, BC and AD have no effect on watermelon quality such as skin resilience, sweetness.