不同促生菌株组合对紫花苜蓿产量和品质的影响

利用前期从苜蓿和小麦根际分离的3株溶磷菌(Bacillus sp.,Pseudomonas sp.和Azotobacter sp.)和1株根瘤菌(Sinorhizobium meliloti)的不同组合研制苜蓿根际专用菌肥,并进行田间随机区组试验,测定其对苜蓿产量和品质的影响。结果表明,单一菌株制作的菌肥处理替代半量磷肥处理后,苜蓿的干草产量和品质较CK(全量磷肥)有所下降,但差异不显著;菌株组合制作的菌肥处理替代半量磷肥处理后,苜蓿的干草产量、粗蛋白(CP)、Ca、P和粗脂肪(EE)含量分别较CK提高10.6%,16.4%,14.1%,11.9%和4.2%,酸性洗涤纤维(ADF)和中性洗涤纤维(NDF)含量分别下降10.9%和7.7%。单一菌株的效果不及菌株组合,经分析比较后推荐S7和Jm170+Jm92+Lx191+S7与半量磷肥配施可代替全量磷肥。

Effects of bio-fertilizers with different PGPR strain combinations on yield and quality of alfalfa

In recent years, bio-fertilizers have emerged as an important component of the integrated nutrient supply system and hold great promise to improve crop yields because increasing use of chemical fertilizers and high productive systems are creating environmental problems. The effects of different combinations of PGPR strains on yield and quality of alfalfa (Medicago sativa) were studied in randomized block field experiments using bio-fertilizers. These were produced using different combinations of three phosphate solubilizing bacteria (Bacillus sp., Pseudomonas sp. and Azotobacter sp.) and one rhizobium (Sinorhizobium meliloti) strain isolated from the rhizosphere of alfalfa and wheat. Hay yield and quality of alfalfa decreased when treated with mono-strain bio-fertilizer (containing 50% phosphatic fertilizer) compared with the control (100% phosphatic fertilizer) although there was no significant difference. Hay yield, content of crude protein (CP), calcium, phosphate and ether extract (EE) increased 10.6%, 16.4%, 14.1%, 11.9% and 4.2% respectively, while acid detergent fiber (ADF) and neutral detergent fiber (NDF) were reduced by 10.9% and 7.7%. The benefit of mono strain bio-fertilizer was inferior to that of mixed strain bio-fertilizer. Strains S7 and Jm170+Jm92+Lx191+S7 with 50% phosphatic fertilizer are recommended as the best treatments to substitute for 100% phosphatic fertilize in alfalfa production.