Effects of Drip Irrigation Fertilizing Reduction on the Yield and NPK Absorption and Utilization of Flue-cured Tobacco

PurposeTo determine the suitable degree of reduction of flue-cured tobacco fertilizer under drip irrigation.

MethodA field experiment was carried out to study the effects of reduction drip irrigation fertilization on the yield and NPK absorption and utilization of flue-cured tobacco, with the treatments of local conventional treatment (CF), nitrogen drip irrigation (DF), 20% reduction of nitrogen drip irrigation (DF−20%N) and 40% reduction of nitrogen drip irrigation (DF−40%N) in 2017.

ResultThe maximum leaf area and average leaf area increased by 40.7% and 20.1%, the concentration content of P and K increased by 28.8% and 31.1% (P<0.05) in tobacco leaf, the accumulation of P and K increased by 8.8% (P<0.05) and 12.3% in the whole tobacco plant, P and K uptake efficiency increased by 35.7% and 45.5% (P<0.05), the mid-high grade leave ratio and average price increased by 28.7% and 17.8% (P<0.05), respectively, in the treatment of DF−40%N. The highest contents of P and K in leaves were found in the treatment of DF−40%N, among the drip irrigation fertilizing treatments. The N accumulation decreased with the decrease of N drip irrigation. The P and K accumulation, N, P and K uptake efficiency, the mid-high grade leave ratio, production value and average price increased, with the decrease of N drip irrigation.

ConclusionIn this experiment, the amount of N should be reduced by 40%, in the stage of top dressing (3∶7 dressing ratio), which benefited for the P and K accumulation, the N, P and K uptake, and the improving of quality grade of tobacco leaves and average price of tobacco.