Cotton, Tomato, Corn, and Onion Production with Subsurface Drip Irrigation - A Review

Abstract

ABSTRACT. The usage of subsurface drip irrigation (SDI) has increased by 89% in the U.S. during the past ten years according to USDA-NASS estimates, and over 93% of the SDI land area is located in just tenubsurface drip irrigation (SDI), the application of irrigation below the soil surface by microirrigation emitters (ASAE, 2007) is growing in usage in the U.S. and around the world. In the ten-year period from 2003 to 2013, SDI in the U.S. increased by 89% from 164,017 to 310,361 ha ( fig. 1) according to USDA-NASS irrigation surveys (USDA-NASS, 2004, 2010. During the same period, SDI averaged approximately 25% of the surface drip irrigation (DI) land area. (Note: microsprinkler and bubbler irrigation are not included in these estimates). However, this comparison can perhaps be skewed by the fact that some of the reported SDI land area contains shallow, annually removed systems that are not intended for multi-year use. The focus of this review is primarily on deeper systems intended for multi-year use.SDI has been the subject of three review articles during the past 20 years: Camp (1998) provided an extensive characterization of the knowledge and studies that had been carried out to date, Rodriguez-Sinobas and Gil-Rodriguez (2012) concentrated on design, uniformity, and soil water redistribution aspects, and Devasirvatham (2009) focused on SDI for vegetable production. The status of the technology was also discussed in the 2000 and 2010 national irrigation symposiums sponsored by ASABE and the Irrigation Association (Camp et al., 2000;Lamm et al., 2012). The goal of this review is to augment and supplement those earlier articles with a focus on the important SDI crops currently grown in the U.S.In 2013, the ten U.S. states with the largest SDI area (289,812 ha) comprised over 93% of the total SDI area but had a wide variation in the ratio of SDI/(SDI+DI) land area ( fig. 2). The variation can probably be explained by the crop production in these states, with DI often used on higher-value crops (typically fruits, nuts, and vegetables) and SDI used on lesser-value commodity crops (e.g., corn, cotton, alfalfa, and other grain crops). There can be also the persistent perception that SDI is harder to manage, mainly because it provides fewer visual cues when irrigation problems are occurring. As a result, many producers growing the higher-value crops choose DI as a less risky option and because the cost of the irrigation system and its installation are not of paramount concern. When growing the lesservalue commodity crops with microirrigation, a deeper, multi-year SDI system that can be amortized over several years is often the only economical option for a producer. This is particularly true in the Great Plains region, where centerpivot sprinkler irrigation has a good economy of scale and where the major sprinkler manufacturers are located (Nebraska). Although the SDI land area in Nebraska and Kansas (near the center of the Great Plains) is relatively small 264TRANSACTIONS OF THE ASABE ( fig. 2), the land area using...