| The southern Jiangxi region belongs to the hilly terrain,and the soil erosion in the newly built navel orange orchard is more serious.The main planted species of the navel orange in the south area is Newhall navel orange,but the organic matter content in the orchard soil is relatively low.Irregular management modes such as clear plowing,blind fertilization,and excessive spraying of pesticides in the orchard all the year lead to serious soil acidification and compaction.In addition,the proportion of red soil in South Jiangxi is 82.1%,and the soil nutrient content is relatively low.For a long time,in order to maintain the high yield of navel orange in southern Jiangxi,the large-scale application of chemical fertilizers has gradually caused the soil problems in orchards in southern Jiangxi.In this study,the typical red soil in southern Jiangxi was taken as the research object,and the optimum ratio of organic fertilizer(dried chicken manure)and inorganic fertilizer(composite fertilizer)was explored.The pot experiment was designed around the growth of Newhall navel orange roots,soil physical and chemical properties,soil Enzyme activity,microbial numbers,microbial metabolic functional diversity,and leaf mineral nutrient content were studied.According to the proportion of nutrients,there are no fertilizer(CK),100%organic fertilizer(T1),80% organic fertilizer and 20% compound fertilizer(T2),60% organic fertilizer and 40% compound fertilizer(T3),40% organic Fertilizer and 60% compound fertilizer(T4),20% organic fertilizer and 80% compound fertilizer(T5),100% compound fertilizer(T6)and other seven treatments.The intention is to clarify the effect of the ratio of organic and inorganic fertilizers on mineral nutrients and soil biological properties of Newhall navel orange.The main research results are as follows:1.Compared with the control group,the fertilization treatment can increase the number of root tips,of which the T5 treatment has the best effect,and it increases by 0.7-3.2 times compared with other fertilization treatments.The fertilization can affect the growth of the aboveground,the trunk diameter,of which the T4 treatment The effect was the best,which increased by 7.17%-20.6% compared with other fertilization treatments.2.Mineral nutrient elements in leaves.Fertilization can increase the content of a large number of elements and some trace elements in the leaves.The order of the content of large amounts of elements in the later stage of the experiment is K> P> Ca> Mg.T3 treatment has the best effect on improving leaf Mg.Compared with treatment,it increased by 9.35%-46.3%.T2 treatment had the best lifting effect on leaf P.Compared with other fertilization treatments,it increased by 3.83%-226.8%.T4 treatment had the best lifting effect on leaf K.Compared with other fertilization treatments,The ratio increased by 32.1%-58.4%.The T2 treatment had the best effect on increasing Ca in leaves.Compared with other fertilization treatments,it increased by4.65%-65.8%.Fertilization could increase the content of Fe,Cu and Zn in the leaves.Fe and Cu content had the best effect,compared with other fertilization treatments,which increased by5.46%-98.6% and 20.7%-133.6%,respectively.T1 treatment on leaf Zn content increased by11.6%-26.2% compared with other fertilization treatments..3.Compared with the control group,the number of microorganisms in the fertilization mode was higher,and the effect of T2 treatment on the rhizosphere soil and non-rhizosphere soil bacteria was the best,which increased by 13.3%-41.7 compared with other fertilization treatments.% And 30.4%-50.0%,T4 treatment had the best effect on increasing the number of rhizosphere soil and non-rhizosphere actinomycetes.Compared with other fertilization treatments,it increased by 5.48%-71.1% and 9.09%-66.7%,T5 treatment had the best effect on increasing the number of fungi in rhizosphere soil,and T4 treatment had the best effect on increasing the number of fungi in non-rhizosphere soil.Compared with other fertilization treatments,it increased by 2.26%-76.6% and 3.16-42.0%.There are more microorganisms than non-rhizosphere soil;fertilization can increase soil urease,phosphatase,and invertase.As the proportion of inorganic fertilizers increases,the activity is higher,and the catalase in the soil is opposite.4.Compared with the control group,fertilization treatment will reduce soil p H.In the later stage of the experiment,each fertilization treatment will improve soil organic matter and effective nutrients to different degrees.Among them,T2 treatment has the best effect on improving organic matter,which is similar to other fertilization treatments.The ratio increased by 0.54%-55.8%.The T5 treatment had the best effect on the improvement of alkalinized nitrogen,and it increased by1.09%-40.4% compared with other fertilization treatments.The T6 treatment had the best effect on the improvement of available phosphorus,compared with other fertilization treatments.Increased by 0.2-2.0 times,T5 treatment had the best effect on improving available potassium,and increased by 0.1-1.5 times compared with other fertilization treatments.5.Diversity of microbial metabolic function.Fertilization can increase the diversity of microbial metabolic function in soil.The best effect of T1-T3 treatment is 1.5-1.7 compared with CK.Rhizosphere microbial metabolic activity is more vigorous.Fertilization can also improve soil.The stability of T1-T4 treated soil is higher,and the stability of rhizosphere soil is better than that of non-rhizosphere soil.In short,fertilization treatment has a better promotion effect on soil nutrients,soil microbial numbers,and microbial metabolic functional diversity,and the effect on rhizosphere soil is greater than non-rhizosphere soil. |
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