不同施肥模式对设施菜田土壤微生物量碳、氮的影响

【目的】 本文利用天津日光温室蔬菜不同施肥模式定位试验，研究了不同施肥模式对设施菜田土壤微生物量碳、氮含量的影响，为设施蔬菜高效施肥和菜田土壤可持续利用提供依据。 【方法】 调查在第 9 茬蔬菜 (秋冬茬芹菜) 和第 10 茬蔬菜 (春茬番茄) 进行。定位试验设 8 个处理，分别为:1) 不施氮；2) 全部施用化肥氮 (4/4CN)；3) 3/4 化肥氮 + 1/4 猪粪氮 (3/4CN + 1/4PN)；4) 2/4 化肥氮 + 2/4 猪粪氮 (2/4CN + 2/4PN)；5) 1/4 化肥氮 + 3/4 猪粪氮( 1/4CN + 3/4PN)；6) 2/4 化肥氮 + 1/4 猪粪氮 + 1/4 秸秆氮 (2/4CN + 1/4PN + 1/4SN)；7) 2/4 化肥氮 + 2/4 秸秆氮 (2/4CN + 2/4SN)；8) 农民习惯施肥 (CF)，除不施氮肥和农民习惯施肥外，其余处理为等氮磷钾处理。在不同生育时期，采 0—20 cm 土壤样品，测定土壤微生物量碳、氮含量，并分析其与蔬菜产量之间的关系。 【结果】 两茬蔬菜不同施肥模式土壤微生物量碳、氮含量总体上均随生育期的推进呈先增后降的趋势。芹菜季较高土壤微生物量碳含量出现在定植后 90 d，土壤微生物量氮较高含量出现在定植后 60 d；番茄季分别出现在定植后 20～80 d 和 60 d。芹菜季 5 个有机无机肥料配施模式土壤微生物量碳、氮含量分别在 185.0～514.6 和 34.3～79.1 mg/kg 之间，较化肥(4/4CN)模式平均分别增加 15.1%～81.7% 和 24.5%～100.0%，其中以配施秸秆模式土壤微生物量碳、氮含量相对较高，平均分别增加 62.0%～81.7% 和 81.1%～100.0%；番茄季 5 个有机无机肥料配施模式土壤微生物量碳、氮含量分别在 120.7～338.0 和 25.5～68.8 mg/kg 之间，较 4/4CN 模式平均分别增加 16.9%～86.9% 和 12.2%～109.3%，又以配施秸秆模式土壤微生物量碳、氮含量最高，平均分别增加 61.4%～86.9% 和 78.2%～109.3%。两季蔬菜不同生育期土壤微生物量碳、氮含量与当季蔬菜产量和定位试验开始以来蔬菜总产量之间均呈极显著正相关关系。 【结论】 同等养分投入量下，有机无机肥料配合施用提高土壤微生物量碳、氮的效果显著好于单施化肥，又以化肥配施秸秆效果更佳；土壤微生物量碳、氮含量与设施蔬菜产量之间呈极显著正相关关系。证明有机无机肥配施，特别是配施一定量的秸秆可有效提高土壤微生物量碳、氮含量，维持较高的菜田土壤肥力，有利于设施蔬菜的可持续和高效生产。

Effects of different fertilization patterns on microbial biomass carbon and nitrogen in greenhouse vegetable soil

Objectives]A fixed-site greenhouse vegetable fertilization experiment has been carried out with rotation of tomato in spring season and celery in autumn-winter season in Tianjin city since 2009. The effects of different fertilization patterns on soil microbial biomass carbon (MBC) and microbial biomass nitrogen (MBN) were investigated in order to provide a scientific fertilization basis for sustainable and high-efficient vegetable production in greenhouse.Methods]The experiment comprises eight treatments: 1) No nitrogen input (No N);2) Complete chemical nitrogen fertilizer (4/4CN); 3) 3/4 N from chemical fertilizer, 1/4 from pig manure (3/4CN+ 1/4PN); 4) 2/4 N from chemical fertilizer, 2/4 from pig manure (2/4CN + 2/4PN); 5) 1/4 N from chemical fertilizer, 3/4 from pig manure (1/4CN + 3/4PN); 6) 2/4 N from chemical fertilizer, 1/4 from pig manure and 1/4 from straw (2/4CN + 1/4PN + 1/4SN); 7) 2/4 N from chemical fertilizer, 2/4 from straw (2/4CN + 2/4SN); and 8) Conventional fertilization (CF). Except for No nitrogen and CF treatments, all the treatments were applied with the same amounts of N, P2O5and K2O nutrients, but varied proportion of nitrogen from different sources. Until this investigation, it was the ninth harvest for autumn-winter season celery and the tenth harvest for spring season tomato. 0–20 cm surface soil samples were collected, the soil MBC and MBN contents were measured at different growth stages of celery and tomato growing seasons, and their correlations with vegetable yields were analyzed.Results]1) Soil MBC and MBN contents in different treatments increased first and then decreased during the studied periods. The relatively higher values for soil MBC and MBN contents respectively appeared at 90 and 60 days after transplanting of celery, and at 20–80 days for soil MBC and 60 days for soil MBN after transplanting of tomato. 2) In the celery season when it was in autumn-winter, the soil MBC and MBN contents were respectively 185.0–514.6 and 34.3–79.1 mg/kg, with increases of 15.1%–81.7% and 24.5%–100.0% in treatments of combined application of manure and/or straw with chemical fertilizers, compared to the 4/4CN treatment, and the highest increases for the contents of MBC and MBN in straw-incorporated treatments were 62.0%–81.7% and 81.1%–100.0%, respectively. In the tomato season when it was in spring, the soil MBC and MBN contents in the combined application of manure and/or straw with chemical fertilizers were respectively 120.7–338.0 and 25.5–68.8 mg/kg, with increases of 16.9%–86.9% and 12.2%–109.3%, compared to the 4/4 CN treatment, and the highest increase values in straw-applied treatments were 61.4%–86.9% and 78.2%–109.3%, respectively. 3) Significant correlation relationships were found between the soil MBC, MBN contents and the corresponding vegetable yield of current season and total yield since the start of the experiment.Conclusions]Under the same input of nutrients, the increase effects in soil MBC, MBN contents are significantly higher in the fertilization patterns of combined application of manure and/or straw with chemical fertilizers. Soil MBC, MBN contents are positively and significantly correlated with the growing season and the total greenhouse vegetable yields. Therefore, the combined use of organic and inorganic fertilizers is capable of increasing the soil MBC, MBN contents and keeping the soil fertility and sustainability in greenhouse vegetable production.