Effects of Different Soil Improvement Organic Materials on Soil Nutrient Supply in Tobacco Fields and Carbon and Nitrogen Metabolism of Tobacco Plants

Purpose To explore the effects of new biochar-based fertilizer on soil nutrient supply and carbon-nitrogen metabolism of tobacco plants, with the aim of improving soil microenvironment and enhancing soil nutrient supply levels.

Methods Using K326 as research material, characteristics of soil nutrient changes, agronomic traits, carbon-nitrogen metabolism, yield and economic benefits of tobacco plants were analyzed under different soil amendments, including conventional fertilization (CK), biochar (BC), biochar-based fertilizer (BF) and organic fertilizer (OF), in field conditions.

Results 1) During the growth period, the contents of nitrate nitrogen, ammonium nitrogen and available phosphorus in 0-20 cm soil layer of BF, BC and OF treatments were totally higher than that of CK. 2) During the growth period, the agronomic traits of flue-cured tobacco under BF, BC and OF treatments were better than that of CK. 3) Compared with CK, BF, BC and OF treatments could increase the activities of α-amylase and sucrose synthetase totally, and reduce the activity of glutamine synthetase. 4) Compared with CK, the yield and economic benefits of BF and OF treatments increased, and the economic benefits of BC treatment increased. Compared with BC and OF treatments, the economic benefits of flue-cured tobacco under BF treatment were increased by 4.52% and 1.76%, respectively; and the proportion of medium-high grade tobacco leaves were increased by 2.03% and 1.56%, respectively.

Conclusion Different soil amendments organic materials can increase soil nutrient supply, enhance carbon-nitrogen metabolism function of tobacco plants, improve the economic benefits of flue-cured tobacco, and the effect of biochar-based fertilizer is the best. The results provide a theoretical basis for the management of soil nutrients in farmland.