Crop response to chiseling and irrigation in soils with a compact A2 horizon
1975
Doty, C.W. | Campbell, R.B. | Reicosky, D.C.
THE OBJECTIVE WAS TO DETERMINE THE YIELD OF MILLET AND SWEET CORN UNDER FOUR SOIL-WATER MANAGEMENT REGIMES AND TO EVALUATE YIELD DIFFERENCES IN TERMS OF OXYGEN STRESS, DEPTH OF ROOTING, AND SOIL WATER STATUS IN A COARSE-TEXTURED SOIL WITH A COMPACT A2 HORIZON. THE EXPERIMENT WAS CONDUCTED ON A VARINA SANDY LOAM SOIL WITH A SLOPE OF LESS THAN 1 PERCENT. MILLET WAS GROWN AS A TEST CROP IN 1969 AND 1970 AND SWEET CORN WAS GROWN IN 1972 AND 1973. THE SPLIT-PLOT EXPERIMENT CONSISTED OF TWO PRIMARY TILLAGE TREATMENTS AS MAIN PLOTS, WITH AND WITHOUT FURROW IRRIGATION. IRRIGATION INCREASED YIELDS DURING DROUGHT PERIODS, BUT YIELDS WERE LESS ON IRRIGATED THAN ON NONIRRIGATED PLOTS DURING PERIODS WHEN THE RAINFALL EXCEEDED PAN EVAPORATION. THE IRRIGATED PLANTS SHOWED GREATER OXYGEN STRESS WHEN HEAVY RAINS FOLLOWED AN IRRIGATION, THAN THOSE ON NONIRRIGATED PLOTS. THE PROBABILITY OF RECEIVING ENOUGH RAINFALL TO SATURATE THE TOP 30 CM OF SOIL SEVERAL TIMES DURING THE GROWING SEASON IS HIGH, AND THIS EXCESS SOIL-WATER CAUSES POOR ROOT AERATION, AND PLANT GROWTH MAY DECREASE SIGNIFICANTLY FROM THE RESULTING LOW SOIL AERATION. CHISELING THE COMPACT A2 HORIZON INCREASED THE ROOTING DEPTH AND PLANT WATER AVAILABILITY IN THE SOIL PROFILE. DURING DRY PERIODS CHISELING PROVIDED A SOIL ENVIRONMENT IN WHICH ROOTS PROLIFERATED TO A GREATER DEPTH AND EXTRACTED ENOUGH WATER TO ELIMINATE OR MINIMIZE WATER STRESS. DURING WET PERIODS, THE CHISELED SOIL PERMITTED WATER TO INFILTRATE AND PERCOLATE TO GREATER DEPTHS, THUS AVOIDING SATURATED CONDITIONS IN THE ROOT ZONE. CHISELING THE SOIL TO A 38-CM DEPTH PROVIDED A ROOTING ENVIRONMENT WHICH PRODUCED SIGNIFICANTLY MORE DRY MATTER AND LARGER NET CROP VALUES. (SKOGERBOE-COLORADO STATE)
显示更多 [+] 显示较少 [-]