Effects of basal topdressing ratio on nutrient and enzymatic activity of sand soil and yield of peanut under mulch drip irrigation system.

For high yield peanut in Northeast Agro-pastoral Ecotone, topdressing ratios of NPK fertilizer (pure N 68.18 kg/hm², P 22.08 kg/hm², and K 174.33 kg/hm²) were used in 6 treatments for investigation of NPK effects. The field experiment was conducted under mulch drip irrigation. Nutrient and enzymatic activities of sandy soil and peanut yield were detected to clarify the optimal basal/topdressing ratio. Results showed that the content of soil organic matter and available N, the activity of urease and sucrase were both increased with the topdressing ratio, while the thicker the soil layer, the lower its content and activity were. The peanut yield was increased firstly and then decreased with the topdressing ratio, which was higher than the traditional fertilization method. The two-year peanut increasing yield range was 3.77%-41.27%. Yields reached the highest at T60, as 6427.7 kg/hm² and 6046.8 kg/hm² respectively. When all of the NK fertilizers were used as topdressing, the yield was not increased obviously, which was average 4.53% higher in two years. In summary, it had the best effect with 40% of the total fertilization amount used as the base fertilizer, and 60% used as topdressing under water and fertilizer integration measures in the area. [ABSTRACT FROM AUTHOR]