摘要
目前人们提到的我国肥料利用率数据都是基于常规公式获得的当季肥料表观利用率的计算结果,并由此认定我国肥料利用率比较低。本文提出养分真实利用率的计算方法,养分真实利用率是作物吸收的养分占种植作物消耗的养分比例。养分来源既包括施用的各种肥料养分,也包括土壤贮存的养分,其公式为:作物吸收的养分量/(施肥量-土壤养分的盈亏量)。养分真实利用率也可采用100%减去养分的损失率来计算,因各种途径未被作物吸收利用并离开耕层土壤的养分才是损失,而贮存在耕层土壤中的养分则不能算作损失。我国耕地土壤肥力的维持和作物吸收的养分都主要来自于各种肥料,因而养分真实利用率的计算公式,基本等同于肥料养分真实利用率的计算公式。利用这一新的公式,我国的肥料养分真实利用率无论是当季还是长期利用率都将远远高于当前文献报道的数据。新的算法获得的肥料养分利用率直接与肥料养分的损失率相对应,将有利于揭示肥料对粮食生产的实际贡献率和损失率,并推动土壤肥力的培育目标及施肥策略与养分损失率相对应,促进施肥技术向减少肥料损失的方向发展,而不是片面地提高目标不太明确却广泛使用的肥料表观利用率。未来大田作物的施肥量并不需要高度依赖测土施肥,而应主要依赖于作物生长对养分的消耗量和养分损失率来确定。
Apparent recovery efficiency (ARE) of applied fertilizers has been commonly calculated as fertilizer use efficiency in China and reported low in a number of literatures. In this paper, a new method is proposed to calculate real nutrient use efficiency (RNUE), which refers to ratio of the nutrients absorbed by plants to the nutrients depleted from the soil. The depleted nutrients may come from the nutrients originally in the soil or from the applied fertilizer. The equation for RNUE calculation could be shown as: Nutrients absorbed by plants / (nutrients from fertilization – negative balance of the soil nutrient pool). RNUE could also be calculated as the difference between 100% and nutrients loss rate. The nutrients not used by plants but depleted from the topsoil are considered lost, while the nutrients remaining in the topsoil are not. Since both the nutrients remaining in soil nutrient pool and the nutrients used by plants come mainly from fertilization, the RNUE can be suggested as the real fertilizer use efficiency (RFUE). Based on the proposed method, the RFUE will be much higher than the ARE reported in China. The loss rate of fertilizer could also be calculated if RFUE is known since their sum is 100%. Thus calculation of RFUE could help us understand real contribution and real loss of the fertilizer in agriculture production and work out proper fertilization strategies, as well, in light of fertilizer loss rate and soil nutrient holding capacity. A proper right fertilization technique should aim to reduce loss rate of the fertilizer, instead of achieving high ARE since the meaning of high ARE is not so clear even though it has been widely used in China. Fertilizer recommendation for main field crops will not depend so much on soil testing, but rather on the knowledge of the consumption and loss rate of nutrients of the soil-crop systems in future.
出处
《土壤学报》
CAS
CSCD
北大核心
2014年第2期216-225,共10页
Acta Pedologica Sinica
基金
国家重点基础研究发展计划项目(2013CB127401)
公益性行业(农业)科研专项经费项目(201203013)
国家自然科学基金项目(41271309)
江苏省科技支撑计划(BE2011821)
IPNI项目资助
关键词
肥料利用率
损失率
施肥技术
氮肥
磷肥
钾肥
Fertilizer use efficiency
Loss rate
Fertilization technique
Nitrogen fertilizer
Phosphorus fertilizer
Potassium fertilizer