Consumptive Use and Salt Accumulation with Trickle Irrigation on Row Crops

Agriculture uses more than 83 percent of all water consumed in the United States west and a similar percentage in New Mexico. Trickle (drip) irrigation offers considerable potential for saving irrigation water while maintaining or even increasing yields. However, little information is available on water use of trickle irrigated crops. In view of the economic importance of chile peppers, a study was initiated to determine the effects of water use and salinity on trickle irrigated chile peppers.

This report summarizes results of research conducted over a seven year period on water use and salinity aspects of trickle irrigation. The major findings from these projects are published in various journal articles and theses listed under References. In addition, each article is briefly described under the Introduction Section of this report.

The study was conducted at the Plant Science Research Center of New Mexico State University. Plots were irrigated through bi-wall trickle tubing buried 10 cm below each crop row. Replicate plots were irrigated at rates equal to 0.6, 0.8, 1.0, 1.2 and 1.4 times the rate applied to control plots.

A maximum yield of 37.2 t/ha of green chile was obtained with 94 cm water, which includes 13 cm rainwater. Yields did increase linearly with irrigation water applied up to the maximum yield. Yields were less for the wettest treatment due to lack of aeration. The optimum tension for maximum yield was about 250 cm at 20 cm below the trickle line. The mean soil salinity in soil with trickle irrigated chile showed little increase over a five-year period, indicating that trickle irrigation of row crops does not have to lead to high salt levels in the plant root zone.