重茬苹果园土壤理化性质变化及对幼树生长结果的影响

目的]采用矮化密植栽培模式,添加土壤有机改良肥,以减轻重茬障碍对新定植苗的危害。方法]以22年生老果园重茬改造园内的土壤和再植苗为试材,连续2年研究果园土壤养分、土壤酶活性以及再植苹果树生长量、产量。结果]果园重置前的有机质含量在2g/kg左右,2009年达到10g/kg以上,2010年又降到5～9g/kg。这说明土壤的有机质正在转化吸收。定植前老果园的碱解氮含量大多在120～150mg/kg,速效磷含量150mg/kg,速效钾含量80～90mg/kg,80%的土壤样本pH低于5.5;2009年土壤碱解氮含量、速效磷含量变化并不大,速效钾含量在470mg/kg左右,全部土壤样本的pH都高于5.5;2010年土壤样本的碱解氮含量100～120mg/kg,速效磷含量30mg/kg,速效钾含量降到200～300mg/kg,80%土壤样本的pH在6.0以上。2010年苹果幼树平均开花率达649.2个/株,2009年却达74.5个/株;2010、2009年苹果单果重不存在差异,多在195.5g左右;2010年苹果单果重达200g,果树产量最高达40669.5kg/hm2。结论]改良后的土壤有机质及N、P、K的含量均有所增加,在随后的2年内有机质及N、P、K含量降低;定植后的幼树生长良好,2010年已进入平稳的丰产期。

Physical and Chemical Properties of Cropping Orchard Soil and Influence on Growth and Yield of Apple Saplings

Objective]Dwarf models and thick planting adding the improvement of soil organic fertilizer were used to reduce barriers for new planting seedlings replanted hazards.Method]Soil and sapling in 22 year-old orchard were used to study orchard soil nutrients,soil enzyme activity and growth of apple trees replanted and yield changes for two consecutive years.Result]Soil organic matter was 2 g/kg in the orchard before reset,and soil organic matter was more than 10 g/kg in 2009,but it dropped to between 5 and 9g/kg in 2010,which showed that soil organic matter was transformed.Nitrogen content was mostly in 120-150 mg/kg in the old orchards before planting,available phosphorus content reached 150 mg/kg,and available potassium content reached 80-90 mg/kg.pH of 80% of the soil samples was lower than 5.5.The changes of soil nitrogen and available phosphorus weren't large in 2009,while available potassium content was 470 mg/kg.pH of all soil samples were higher than 5.5.Soil samples nitrogen content was 100-120 mg/kg in 2010,available phosphorus was 30 mg/kg,and available potassium content was 200-300 mg/kg.pH of 80% soil samples was above 6.0.Average flowering rate reached 649.2 /plant in 2010,but in 2009 it was 74.5 /plant.The single weighs in 2010 was as the same as those in 2009.Most of them were around 195.5 g.Apple weighs in single was 200 g,and fruit trees yield was up to 40 669.5 kg/hm2 in 2010.Conclusion]Organic matter and N,P,K content in improved soil were increased,and in the ensuing two years they decreased.Saplings grown well after planting and in 2010 they entered a stable yield period.