不同剂型联合固氮菌肥对青稞促生效应和固氮能力研究

利用联合固氮菌(Associative nitrogen-fixing bacteria)制作菌肥,设7个处理:CK1(基质对照,泥炭拌种)、CK2(半量¹⁵N尿素)、1N(全量氮肥)、1/2NL(半量¹⁵N尿素₊液态菌肥)、NL(液态菌肥)、1/2NS(半量¹⁵N尿素₊固态菌肥)、NS(固态菌肥),通过温室盆栽实验,利用¹⁵N稳定性同位素稀释法,测定其对青稞(Hordeum vulgarevar.nudum Hook.f.)生长及固氮能力的影响。结果表明,本研究研制的联合固氮菌肥符合《农用微生物菌剂》质量标准(GB20287-2006),且固体菌肥的有效活菌数在检测的各个时期都高于液体菌肥。对于株高、地上生物量、地下生物量、根冠比来说,联合固氮菌肥与半量氮肥(110kg·hm^-2)配合施用,表现出与全量氮肥相近的促生效果,即可节约近一半的氮肥用量(110kg·hm^-2);固体菌肥和液体菌肥的固氮百分率和固氮量分别为17.44%、14.03%和22.87 kg·hm^-2、21.29 kg·hm^-2。并且,固体菌肥对青稞生长的促进作用优于液体菌肥。

Effect of Associative Nitrogen-fixing Biofertilizer Produced with Different Carriers on Growth and Nitrogen Fixing Ability of Hordeum vulgare var.nudum Hook.f.

The associative nitrogen-fixing biofertilizer as a new green fertilizer has been paid more attention recently.The effect of biofertilizer produced with associative nitrogen-fixing bacteria and different carriers(LB liquid culture medium and peat) on the growth and nitrogen fixing ability of Hordeum vulgare var.nudum Hook.f.was studied through pot experiment in greenhouse.¹⁵N isotope dilution method was employed with 7 treatments,including CK1(peat),CK2(half application rate of ¹⁵N labeled urea),1N(whole application rate of urea),1/2NL(half application rate of ¹⁵N labeled urea+liquid biofertilizer),NL(liquid biofertilizer),1/2NS(half application rate of ¹⁵N labeled urea+peat biofertilizer),and NS(peat biofertilizer).The results indicate that the associative nitrogen-fixing biofertilizer accorded with the quality criterion of agricultural microbial fertilizer of China(GB 20287-2006) and the number of effective bacteria in peat biofertilizer was much higher than liquid biofertilizer.The effect of the biofertilizer added with half application rate of chemical nitrogen fertilizer(110 kg·hm^-2) on plant height,aboveground biomass,underground biomass,and root/shoot ratio was similar to the whole application rate of chemical nitrogen fertilizer(220 kg·hm^-2),suggesting that the half chemical nitrogen fertilizer could be saved.The nitrogen fixing percentage and amount of peat biofertilizer and liquid biofertilizer were 17.44%,14.03% and 22.87 kg·hm^-2,21.29 kg·hm^-2,respectively.The peat biofertilizer had better growth performing effect than liquid biofertilizer.