National Engineering Handbook, Part 652, Irrigation Guide

Excerpts from the Introduction: The Irrigation Guide provides technical information and procedures that can be used for successful planning, design, and management of irrigation systems. It is a guide only and does not imply or set Natural Resources Conservation Service (NRCS) policy. The Irrigation Guide includes current information and technical data on irrigation systems and hardware, automation, new techniques, soils, climate, water supplies, crops, tillage practices, and farming conditions. Included are irrigation related technical data for soils and irrigation water requirements for crops. Planning for an irrigation system should take into account physical conditions of the site, producer resources, cropping pattern, market availability, water quantity and quality, and effects on local environment. Economics should provide the basis for sound conservation irrigation decisions, but may not be the ultimate consideration. This is because many other factors may influence final decisions.

引言节选：本《灌溉指南》提供可用于成功规划、设计与管理灌溉系统的技术资料与操作流程。本指南仅为参考性文件，并不代表或制定自然资源保护局（Natural Resources Conservation Service，NRCS）的官方政策。《灌溉指南》涵盖了灌溉系统与配套硬件、自动化技术、新兴工艺、土壤、气候、水源、作物、耕作措施以及农业生产条件等方面的最新资讯与技术数据，其中还包含与土壤相关的灌溉技术数据，以及作物灌溉需水量相关内容。开展灌溉系统规划时，需综合考量场地物理条件、生产者资源状况、种植结构、市场可获得性、水量与水质，以及对当地生态环境的影响。经济效益应为合理的节水灌溉决策提供支撑，但未必是最终考量因素，因为诸多其他因素均可能对最终决策产生影响。