长期施用不同肥料对小麦玉米间作产量、氮吸收利用和土壤硝态氮累积的影响

对连续14年施用不同肥料后,春小麦.春玉米间作下,土壤硝态氮的累积和分布,作物产量及对氮素的吸收利用进行了研究。结果表明,在施农家肥120t.hm2(M)、绿肥45t.hm2(G)、秸杆10.5t.hm2(S)、N375kg.hm2(N)、农家肥60t.hm2+N187.5kg.hm2[1/2(M+N)]、绿肥22.5t.hm2+N187.5kg.hm2[1/2(G+N)]、秸杆5.25t.hm2+N187.5kg.hm2[1/2(S+N)]和CK等8个处理中,土壤剖面硝态氮的累积和分布以N处理最高,地上部N浓度和吸N量以N、1/2(M+N)和1/2(G+N)处理较高,但3处理间无明显差别。间作小麦子粒产量和生物学产量以M、G、1/2(M+N)和1/2(G+N)等处理较高,间作玉米子粒产量和生物学产量以1/2(G+N)、N、G和1/2(M+N)等处理较高。氮肥利用率以1/2(S+N)处理最高,1/2(M+N)和1/2(G+N)低于1/2(S+N)、S和N处理,但高于M、G处理。说明氮肥与农家肥或绿肥配合施用,既能增加作物产量,提高氮素吸收利用,又可减少土壤中硝态氮的累积。

Effect of long-term fertilizer application on yield,nitrogen uptake and soil NO-3-N accumulation in wheat/maize intercropping

After 14 years long-term fertilization, NO~-_3-N accumulation in soil profile, nitrogen uptake and utilization by intercropped wheat and maize was investigated. The results showed that among manure120 t/hm~2(M),green manure 45 t/hm~2(G),straw 10.5 t/hm~2(S), N375 kg/hm~2(N), manure 60 t/hm~2 N187.5 (kg/hm~2), green manure 22.5 t/hm~2 N187.5kg/hm~2, straw 5.25 t/hm~2 N187.5 kg/hm~2and CK treatments,soil NO~-_3-N concentration and accumulation was the highest with N 375 km/hm~2application, above-ground nitrogen concentration and nitrogen uptake were higher with N, 1/2(M N) and 1/2(G N) treatments, but among three treatments existed no significant difference. Grain yields and biomass of intercropped wheat were higher with M,G,1/2(M N) and 1/2(G N) treatments, and intercropped maize were higher with 1/2(G N), N, M and 1/2(M N) treatments. Nitrogen use efficiency was the highest with 1/2(S N) treatment, 1/2(M N) and 1/2(G N) treatment were lower than 1/2(S N),S and N treatments,but were higher than that of M and G treatments. It suggested that nitrogen fertilizer combined with organic matter could increase grain yields, enhance nitrogen concentration and uptake, reduce nitrate accumulation in soils.