| Contemporarily,the improvement of Chinese living standards results in the increasing development of animal husbandry,especially,the scale and consumption of pork has become the world's largest industry in China,leading to numerous dead pigs annually due to the natural pig mortality rate of 10-20%in the highly intensive animal production system,and showing an elevated risk to the environment and or even to human health.The use of huge amount of chemical fertilizer to ensure high crop yields in China has caused serious agricultural ecology and environmental issues,including soil compaction,acidification,decreased organic matter and water eutrophication.Animal carcasses hydrolyzed by sulfuric acid solution to create compound liquid amino acids is an effectively strategy to protect the environment.However,how to efficiently utilize these liquid amino acids does cause public concern.In the present study,effects of different amounts of compound liquid amino acids from animal carcasses amended into matured composts as additives on the solid-state fermentation of plant growth-promoting rhizobacteria(PGPR)Bacillus amyloliquefaciens SQR9 were compared and subsequently plant growth promotion efficiency of the produced bio-organic fertilizers were investigated to explore the optimum additive concentration of the amino acids for creating novel bio-organic fertilizer(BIO),after that the plant growth promotion effects of novel bio-organic fertilizers on different crops by pot experiments and on cucumber by field experiments were investigated.The research will not only sought a cheap medium for producing low-cost,high-quality BIO,but also guarantees sustainable development of animal husbandry.1.Effects of different amounts of compound liquid amino acids from animal carcasses amended into matured composts as additives on the solid-state fermentation of plant growth-promoting rhizobacteria(PGPR)Bacillus amyloliquefaciens SQR9 were compared and subsequently plant growth promotion efficiency of the produced bio-organic fertilizers were investigated.Characters of strain SQR9 and compound liquid amino acids were also investigated.Results showed Results showed that the optimal amendment concentration of liquid amino acids was 20%,which resulted in a maximum biomass of functional strains with the number of 2.25 ×108 CFU/g(dry weight,the same follow)that was 3 times than the control without adding liquid amino acids.Pot experiment results showed that cucumber plant growth promotion effects of the novel bio-organic fertilizer were superior to the other treatments amended with different concentrations of liquid amino acids and the control.The number of strain SQR9 in rhizosphere soil reached 2.51 ×105 CFU/g soil.2.Plant growth promotion effects of the novel bio-organic fertilizer produced by adding compound liquid amino acids were better than that produced by amending chemical fertilizers with equal nutrients to compound liquid amino acids.Results from pot experiments of different crops showed the novel produced BIO resulted in greater plant growth compared to the treatment amended with BIO produced by adding chemical fertilizer as additive,the treatment amended with BIO produced by adding none additive,the treatment amended with organic fertilizer and the treatment amended with organic fertilizer amended with liquid amino acids.Meanwhile,the treatments amended with the fertilizers with strain SQR9 showed better plant growth than the others,indicating that strain SQR9 exhibited plant growth promotion effect.Moreover,compared to the treatment amended with BIO produced by adding chemical fertilizer as additive,the treatment amended with novel BIO is more beneficial for the function enhancement of the strain SQR9.In the rhizosphere of different crops,significant higher number of functional microbes were observed in the treatment amended with novel BIO.3.Two seasons of field experiments were conducted to evaluate the plant growth promotion effects of the novel bio-organic fertilizer produced by adding compound liquid amino acids.Results showed that in the first season field experiment,the treatment amended with bio-organic fertilizer produced by adding compound liquid amino acids(AA+9)showed highest cucumber yield with the value of 30820.95 kg ha-1,which was increased by 5935,2582,1999and 3965 kg ha-1 when compared to treatments amend with organic fertilizer(OF),BIO produced by adding none additive(OF+9),organic fertilizer amended with liquid amino acids(AA),and BIO produced by adding chemical fertilizer as additive(CF+9).The number of strain SQR9 in AA+9 treatment rhizosphere soil reached 1.45 × 105 CFU/g soil,which was significantly higher than other treatments.In the second season field experiment,the treatment amended with bio-organic fertilizer produced by adding compound liquid amino acids(AA+9)showed significantly higher cucumber yield with the value of 27530kg ha-1 than other treatments,which was increased by 6289,3506,3323,and 2977 kg ha-1 when compared to treatments amend with organic fertilizer(OF),BIO produced by adding none additive(OF+9),organic fertilizer amended with liquid amino acids(AA),and BIO produced by adding chemical fertilizer as additive(CF+9).The number of strain SQR9 in AA+9 treatment rhizosphere soil reached 1.51 × 105 CFU/g soil,which was significantly higher than other treatments.To sum up,adding 20%of liquid amino acids effectively enhanced the growth of functional microbes in the organic fertilizer,and the produced novel BIO showed outstanding plant growth promotion effect. |
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