Effects Of Four Kinds Of Bait And Batio On Growth And Reproduction Of Earthworms And Quality Of Compost

At present,China has a huge amount of agricultural waste,of which livestock,poultry manure and straw account for a large proportion.The annual output is as high as 13.40 billion tons and 700 million tons,respectively,and the utilization rate is generally less than 40%.Earthworm composting is an effective and green waste treatment technology.By the intestinal function of earthworms and microbes,we can fully utilize a large amount of waste as well as to get the better quality of earthworm feces production.Recent research work are mostly focused on cow dung and/or other single raw materials,but the research on the ratio of multiple raw materials based on local resources has been relatively less studied.This study therefore aims to investigating the status of raw materials in various places.In the current study we selected four types of bait,cow dung,wheat straw,apple pomace and medicinal dregs according to the characteristics of the raw materials,and the cow dung was used as the main material in which the other three baits were mixed,which were cow dung Straw,cow dung pomace and cow dung medicinal dregs combination,each mixed bait combination was set with three mixing ratios?dry matter weight ratio is 1:1?1:2?1:3?,hence we had study four kinds of bait and matching ratio,the effects of earthworm growth,reproduction and compost quality.The main conclusions are as follows:1. Different bait and combination ratio had a significant effect on the growth and reproduction of earthworms.The cow dung pomace combination was more suitable for the growth and reproduction of earthworms than the cow dung straw and cow dung medicinal dregs combination.The average body weight of the largest earthworm was 65.79%and 75%higher than the cow dung straw and cow dung medicinal dregs combination,respectively.Under the ratio combination,the combination of cow dung straw and cow dung residue was the best for the growth and reproduction of earthworms when the material ratio was 1:1.The average weight of earthworms reaches 0.38g and 0.36g respectively,which was 31.03%higher than the1:3 combinations 9.09%,the cow dung and pomace combination had the best earthworm growth condition when the material ratio was 1:3.The average weight of the earthworm was0.63g,which was 12.5%higher than the 1:1 combination.The maximum number of cocoons produced per day was 1:1.The above results indicated that an appropriate increase in the proportion of pomace was more suitable for the growth of earthworms,while an appropriate increase in the proportion of cow dung was more suitable for the reproduction of earthworms.2. Different bait and combination ratio could significantly affect the physical and chemical properties of earthworm compost.The content of total nitrogen,total phosphorus and total potassium in the bait after earthworm composting augmented significantly,and the combination of cow dung and pomace increased relatively.Under the same bait and different proportion combinations,when the bait ratio was 1:3,the cow dung pomace combination had the largest increase,which was by 104.39%,30.92%and 85.72%higher than the initial content,the cow dung straw and cow dung medicinal residue combination were in the bait compared with 1:1,increased exhibiting highest values.The cow dung straw combination increased by 10.90%,62.00%and 36.09%compared with the initial content.As compared with the initial content,the cow dung residue combination increased by 19.95%,4.03%and 24.26%respectively.3. We had investigated that different bait and combination ratio significant affected the biological characteristics of earthworm compost.Among the three different bait combinations of cow dung straw,cow dung pomace and cow dung medicinal dregs,significantly increased the number of microbes such as bacteria,fungi and actinomycetes in the cow dung pomace compost which was 1.76 times and 3.69 times greater of the cow dung straw combination respectively.And 2.46 times,1.75 times,3.06 times and 2.58 times of the cow dung combination.Under the same bait and different ratios,when the ratio of cow dung and pomace bait was 1:3,the number of bacteria,actinomycetes and fungi in the compost product was significantly increased,which was 15.60×10⁸CFU·g^-1,93.21×10⁶ CFU·g^-1,29.01×10⁵CFU·g^-1,the amount of bacteria,actinomycetes,and fungi was the highest when the combination of cow dung straw and cow dung residue was 1:1,and the number of bacteria,actinomycetes,and fungi of cow dung straw combination was 8.85×10⁸CFU·g^-1,33.4×10⁶CFU·g^-1,11.79×10⁵ CFU·g^-1,the amount of bacteria,actinomycetes,and fungi in cow dung4. The safety of earthworm composting with different combinations of bait and ratio was significantly different.In the combination of cow manure straw 1:1,cow manure pomace 1:3,and cow manure medicinal residue 1:1,the content of heavy metals in the cow manure pomace compost product was lower,and the Cd,Pb,Cr content were lower than the cow manure straw combination respectively by 40.00%,25.61%,and 51.54%,which were 75%,51.01%,and73.57%lower than cow dung combination.5. Additionally different bait and combination ratio had a significantly enhanced the content of amino acids and plant hormones ABA and IAA in earthworm compost products.In the combination of cow manure straw 1:1,cow manure pomace 1:3 and cow manure medicinal residue 1:1,the amino acid content of the cow manure pomace compost product was relatively high,which was 1.96 combined with cow manure straw and cow manure medicinal residue respectively.The combination of cow dung straw and cow dung residue significantly enhanced the the ABA content of plant growth hormone which was 1.37 times and 1.52 times of the respectively,and the biggest increase compared to the starting material,an increase of 47.13%,in the cow dung residue combination.The IAA content was higher,which was 1.30 times and3.69 times of the cow dung straw and cow dung pomace combination respectively.The cow dung pomace combination had the largest increase from the initial content,an increase of171.74%.In conclusion,the results elucidated the positive role of earthworms inoculation in improvement of the overall quality of the compost product.The cow dung and fruit residue combination with earthworms had the best composting effect and was most suitable for the growth and reproduction of earthworms.Appropriately increasing the proportion of pomace could improve the efficiency of composting and the quality of earthworm manure.Properly increasing the proportion of cow dung could enhance the composting effect of earthworms and improve the quality of earthworm manure.In this study,we found a better combination of earthworm composting materials.In addition,the heavy metal content could be used as the most basic standard for whether earthworm manure could be applied to farmland.It is also recommended to use plant growth hormone?ABA and IAA?and amino acid content as the difference between earthworm manure.It is an important quality evaluation index with other organic fertilizers and chemical fertilizers.The above conclusions provide a theoretical reference for the local earthworm breeding raw materials and ratio screening,and also provide a theoretical basis for the resource utilization of cow dung,wheat straw,apple pomace and medicine residue.