大麦长期肥料效率和土壤养分平衡

基于19年田间定位试验, 通过测定氮、磷、钾肥不同配施处理下, 大麦地上部生物量、产量及籽粒和秸秆中各养分含量, 研究了大麦生长期土壤和环境养分供应状况、肥料效率和土壤养分表观平衡。结果表明, 不施肥条件下, 平均每年大麦可从土壤和环境中吸收氮、磷和钾素44.5、10.7和52.5 kghm^-2; 大麦籽粒中氮、磷、钾含量平均为17.3、3.48和4.18 gkg^-1, 秸秆中为4.85、0.64和17.5 gkg^-1。所吸收的氮素和磷素分别有75.7%和83.5%被转运至籽粒中, 但钾的转运率仅为18.8%。大麦生产单位籽粒所需的氮素和钾素相当, 约为吸磷量的5~6倍。每生产1000 kg籽粒, 需要吸收氮素22.3 kg、磷素4.0 kg和钾素20.5 kg。19年平均氮、磷和钾肥的表观利用率分别为29.0%、12.8%和71.8%, 累积回收率为75.3%、63.6%和203.2%。在氮磷钾平衡施肥条件下, 每年土壤氮素和磷素可盈余18.4 kg hm^-2和6.9 kghm^-2, 但是土壤钾素平均每年亏缺43.8 kg hm^-2; 这种基础养分供给处理可维持每年大麦产量2350 kghm^-2左右。

Fertilizer Efficiency and Soil Apparent Nutrient Balance for Barley under Long-Term Fertilization

In the 19-year located fertilization experiment in barley, five treatments were designed with different combinations of nitrogen (N), phosphorus (P), and potassium (K) fertilizers. The natural productivities of nutrient elements from soil and environment, fertilizer efficiencies and soil nutrient apparent balances were investigated by measuring aboveground biomass, grain yield, and nutrient contents in grain and straw. Under no fertilization condition, the amounts of nutrient supply from soil and environment were 44.5, 10.7, and 52.5 kg ha^-1 for N, P, and K elements, respectively. The average N, P and K contents were 17.3, 3.48, and 4.18 gkg^-1 in grainand 4.85, 0.64, and 17.5 gkg^-1 instraw, respectively. The percentages of nutrient elements translocated from aboveground organs into grain were 75.7% for N, 83.5% for P and 18.8% for K. This result indicated that the most of N and P absorbed by plant were ultimately deposited into grains, whereas more than 80% K absorbed remained in straws. For producing 1000 kg grain, barley plant required absorptions of 22.3 kg N, 4.0 kg P, and 20.5 kg K. Clearly, the P requirement was 5–6 times the requirement of N or K. The average apparent fertilizer use efficiencies for N, P and K fertilizers were 29.0%, 12.8%, and 71.8%, respectively. The average accumulative recovery efficiencies of N, P and K over 19 years were 75.3%, 63.6%, and 203.2%, respectively. Under balanced fertilization with fixed N, P and K inputs, there were annual net gains of 18.4 kg ha^-1 for N and 6.9 kg ha^-1 for P, but a net loss of 43.8 kg ha^-1 for K in soil. Such soil condition produced barley yield of 2350 kg ha^-1 per year.