NITROGEN CYCLING AND LOSSES FROM DAIRY FARMS

被引：105

作者：

JARVIS, SC

机构：

[1] AFRC Institute of Grassland and Environmental Research, Okehampton, Devon

来源：

SOIL USE AND MANAGEMENT | 1993年 / 9卷 / 03期

关键词：

D O I：

10.1111/j.1475-2743.1993.tb00937.x

中图分类号：

S15 [土壤学];

学科分类号：

0903 ; 090301 ;

摘要：

The concern over leakage of nitrate into waters and loss of other forms of N to the environment demands an appraisal of N flows within complete systems. The grassland N cycle is complex, with interactive controls over fluxes and transformations, and has the potential for considerable losses. Although there are data from experimental systems, a total comprehension of flows is not yet possible. Intensive dairy farming has a number of opportunities for leaks. A 'model' system in SW England has an annual input of 25.6 tonnes of N: of this only 20% is transferred into protein or milk, a further 46% is lost to the wider environment, 34% is as yet unaccounted for and much is recycled. Recent research has provided new techniques to decrease losses. To meet the joint requirements of production and environmental concerns we need to consider N flows and supplies on an integrated, whole farm basis, and to take better account of mineral N in the soil profile in relation to current crop demand, local climate and past sward management.

引用

页码：99 / 105

页数：7

共 35 条

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