Nutrient budget and soil nutrient status in greenhouse system | 温室栽培系统的养分平衡及土壤养分变化特征

Chinese. 【目的】弄清中国典型地区温室栽培系统的养分收支状况及其对土壤养分累积变化的影响,为节肥增效,实现温室生产的可持续发展提供依据。【方法】选取中国典型温室栽培地区山东寿光具有代表性的18个温室大棚为研究对象,通过对各温室肥料投入、作物种类及产量等情况的详细调查及土壤分析,研究温室系统养分的收支平衡及土壤养分变化特征。【结果】（1）在中国典型温室栽培生产基地,每年氮、磷、钾养分的平均投入量为4 088、3 656和3 438 kg?hm-2,其中随化肥投入的氮、磷、钾养分分别占到各养分总量的63%、61%和66%,是土壤养分的主要来源。（2）温室栽培条件下,氮、磷、钾养分的利用率分别仅为24%、8%、46%,且施用比例（1s0.9s0.8）与作物的需求比例（1s0.3s1.4）严重失衡。温室土壤有机质相对缺乏,而氮、磷、钾则大量累积,其理论盈余量分别为3 214、3 401和2 322 kg?hm-2。（3）温室土壤有机质、全氮、硝态氮、速效磷、速效钾的含量均显著高于露地土壤,且耕层（0―20 cm）的累积量最高,其平均含量分别为露地土壤的1.4倍、1.9倍、21.2倍、5.4倍和3.7倍。各养分在土壤剖面存在不同程度的向下迁移现象,其中NO3-的大量累积和向下迁移是造成当地地下水污染风险的关键因子。【结论】温室栽培系统中,盲目过量的施肥,不仅造成肥料资源的浪费,破坏土壤－植物的养分供需平衡,影响蔬菜品质,同时氮、磷的随水淋失也会带来巨大的环境风险。温室生产中不仅应重视高质量有机肥的投入,还应根据作物的需肥特性及土壤供肥能力进行计量施肥,以实现温室生产高效、优质、环境友好的发展目标。

English. 【Objective】 This paper researched on nutrient budget and its effects on soil nutrient status in typical greenhouse system in China to provide a basis for raising the utilization rate of fertilizers and maintaining the sustainable development of agriculture in greenhouse. 【Method】 By investigating the management of 18 representative greenhouses in Shouguang, Shandong province and analyzing both the greenhouse and open field soil samples, the soil nutrient budget and the trend of nutrient accumulation and translocation in soils were studied. 【Result】 Under greenhouse cultivation,the average annual input amounts of N, P2O5 and K2O were, respectively, 4 088 kg?hm-2, 3 655 kg?hm-2, and 3 437 kg?hm-2 and 63%, 61%, and 66% of the total input amount of N, P2O5 and K2O were provided by chemical fertilizers which were the main source of soil nutrient. In greenhouse system, the utilization rate of N,P2O5, and K2O were only 24%, 8%, and 46% and the input ratio of N,P2O5, and K2O (1s0.9s0.8) was quite different from the uptake ratio (1s0.3s1.4) , thus it caused an overplus of N,P2O5, and K2O in soil and the theoretical surplus were 3 214 kg?hm-2, 3 401 kg?hm-2, and 2 322 kg?hm-2, respectively. In the greenhouse soil, the content of organic matter, total nitrogen, nitrate nitrogen, available phosphorus and available potassium were all increased and their maximum values were observed in the topsoil (0-20 cm) , with an average value being 1.4 times, 1.9 times, 21.2 times, 5.4 times, and 3.7 times than that of the open field soil, respectively. Greenhouse soils displayed apparent phenomena of nutrients leaching downwards to the bottom soil, especially NO3-, which would cause a potential risk to the quality of groundwater in the area. 【Conclusion】 Under greenhouse cultivation, it is necessary to apply more organic manure and provide nutrients according to the crop requirements and soil nutrient supplying ability as it could not only produce high crop yield,but also beneficial to balance the soil nutrient and improve the utilization rate of fertilizers, then there will be no significant surplus of nutrients which may emit or leach out of soil into environment.