SOME FACTORS AFFECTING RATES OF IRRIGATION WATER ENTRY INTO RAMONA SANDY LOAM SOIL

Publisher Website
Google Scholar
Abstract
Rates of water entry into Ramona sandy loam soil, where irrigations were applied to singletree basins in an orange orchard, were measured over a 7-yr. period. There were 8 treatments with 3 replications of each. Half of the basins were fertilized with ammonium sulfate at the rate of 2 lbs. N/basin/yr., and half with urea at the same nitrogen rate. Cultural practices for weed control, including hoeing, oil spray, and mowing, were so varied that there were 4 levels of litter accumulation on the soil surface. The ammonium sulfate, high organic matter treatment was more erratic than the others, but gave the highest infiltration rates. Whereas previous reports indicated that high application of ammonium sulfate depressed infiltration rates, these moderate application rates did not. With low levels of surface organic matter, infiltration rate differences between fertilizers were not significant, but with high levels of organic matter the differences were highly significant, ammonium sulfate giving the high rate. Increases in organic matter caused significant infiltration rate increases in all instances. At the conclusion of the field work, soil samples were taken for laboratory determinations of structural factors. Bulk density measurements by undisturbed cores showed the effects of surface litter at the 1/2-2 1/2 inch depth, but not at the 5-7 inch depth. Bulk density values by a standard compaction method after air-drying of soil samples showed significant effects of weed control practices. Aggregation measurements showed some trends, but the differences were barely significant.

This publication has 0 references indexed in Scilit: