根区局部灌溉对有机无机肥配施土壤微生物和玉米水分利用的影响

Effect of partial root-zone irrigation on soil micro-organism and maize water utilize under combined application of organic and inorganic fertilizers

在不同有机无机肥配施条件下,研究3种灌水方式,即常规灌溉(CI)、固定部分根区灌溉(FPRI)和分根区交替灌溉(APRI)对土壤微生物数量和玉米水分利用的影响。结果表明:有机无机肥配施能增加土壤微生物的数量,但并不随有机肥比例的增加一直递增。在相同灌溉方式下,以60%化肥+40%有机肥(F3)施肥处理效果较好,拔节期、孕穗期和灌浆期3个时期细菌、真菌和放线菌数量较其他施肥处理高。而在相同施肥条件下,APRI和FPRI土壤细菌、真菌和放线菌的数量高于CI处理。与CI相比,FPRI和APRI分别平均节水14.7%和16.9%,水分利用效率则分别平均提高了20.0%和10.4%。这表明根区局部灌溉能创造良好的土壤生物环境,促进微生物的代谢和繁殖,提高土壤中微生物的数量,节约灌水量和提高水分利用效率。

A pot experiment was carried out to study the effects of three kinds of water irrigation, i.e. conventional irrigation （CI）, fixed partial root-zone irrigation （FPRI） and alternate partial root-zone irrigation （APRI） on the number of soil microorganism and maize water use under different combined application of organic and inorganic fertilizer. The results showed that the combined application of organic and inorganic fertilizer increased the number of soil microorganism which, however, did not keep on increasing with the increase of the use ratio of organic fertilizer. Under the same irrigation treatment, 60 % inorganic fertilizer combined with 40 % organic manure treatment increased the number of soil bacteria, fungi and actinomycetes in jointing, booting and filling stage than other treatments. While under the same fertilization level treatment, the number of soil bacteria, fungi and actinomycetes in APRI and FPRI treatments were higher than CI treatment. Compared with CI treatment, FPRI and APRI treatments average saved irrigation water by 14.7 % and 16.9 %, and water use rate increased by 20.0 % and 10.4 96. Above results showed that partial root-zone irrigation （PRI） created a good soil biological environment, promoted the metabolism and reproduction of the microorganism, the number of soil microorganisms, and saved irrigation water use amount and raised water utilizing rate.