Evaluation of the Potential to Improve Alfalfa for Production Under Less than Optimum Moisture Conditions

The use of alfalfa was explored as a means of conserving New Mexico’s supplies of fresh water. Alfalfa is grown on approximately one-fifth of New Mexico’s irrigated acreage. Competition for water has been increasing. The rising cost of energy has also led to increased concern over the use of fresh water supplies for agricultural production. Plant breeding procedures were used to increase alfalfa’s yield potential when given limited quantities of irrigation. The purpose was to increase alfalfa’s ability to survive and grow under less than optimum irrigation and to increase its ability to respond to irrigation and/or rainfall when available. Field, greenhouse, and laboratory experiments were conducted to find techniques that would: identify germplasm sources for these traits; evaluate and identify individual genotypes within these sources; evaluate the potential of the techniques and the new populations developed; and evaluate irrigation management techniques that would maximize the yield potential of the selected populations with less than optimum amounts of irrigation. Germplasm sources, selection techniques, elite genotypes, and irrigation management techniques were developed. The result is that water conservation is feasible with alfalfa with little sacrifice in yield potential. The selected populations produced more forage than unselected populations when given the same amount of water. The advantage of the selected populations was greatest at the lower levels of irrigation. Alfalfa appeared to have a greater response to water applied early in the growing season than late. The combination of selected populations and irrigation management allows for maximum water conservation with alfalfa.