09/05/05 Green manure crops in rotation

At the University of Idaho Parma research center Saad Hafez has been touting the benefits of green manure crops for more than a decade. These second crops which are typically oilseed radishes or mustards rebuild the soil and cut nematode populations. As organic matter builds, water-holding capacity increases, compaction and erosion decrease. HAFEZ "Compared to the cost of using neumatacides or fungicides it's less than half of the cost." A nematology specialist Hafez worked on a green manure system that would fit Idaho agriculture. It hasn't taken off here but it's being employed by growers in other states. Hafez says timing is the issue in Idaho because the green manure crop must to be planted right after harvest. HAFEZ "They are just tied up with equipment and with the labor. One of the other constraints for this practice is the ability for irrigation water. If we get a shortage of water well we cannot plant another crop in the fall which you need to irrigate." Hafez says new oilseed radishes should entice more Idaho potato and sugarbeet growers into giving green-manure crops a try within a few years. Voice of Idaho Agriculture Bill Scott