Submitted to: Soil & Tillage Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 25, 1998
Publication Date: N/A
Interpretive Summary: Small grain production in interior Alaska is often limited by lack of soil water during the growing season. Conservation tillage practices that have proven effective for conserving soil water in other parts of the US have been proven effective in Alaska for controlling wind erosion, but have not been evaluated for conserving soil water. Thus, field studies were conducted to compare several combinations of tillage and straw management. No-till resulted in greater production of barley than conventional or minimum till. However, no-till also resulted in severe infestation of grassy weeds which prohibited the continuous production of barley. These data thus show the potential that no-till has for increasing barley production in Alaska, but also illustrate the need for research on economic grass weed control that will be compatible with no-till barley production. Such a system will increase barley production in interior Alaska.
Technical Abstract: Small grain production in subarctic regions is often curtailed by the lack of soil water and therefore necessitates the use of tillage and straw management practices that conserve soil water. Barley was grown utilizing four tillage treatments and three straw treatments near Delta Junction, Alaska from 1988 through 1991. Soil water content was determined biweekly during the year and grain yield was assessed in each plot. No tillage resulted in greater yield (250 kg ha**-1) than a conventional and fall chisel-plow tillage, but only in 1990. Grain yield was at least 200 kg ha**-1 greater on plots that were devoid of stubble and loose straw compared to plots with stubble or with stubble and loose straw in 1990 and 1991. Barley consumed more water to achieve the greater yield from plots subject to no tillage or devoid of stubble and loose straw. Water-use efficiency did not vary among tillage treatments. Depletion of soil water occurred from May (planting) to July (anthesis) whereas soil water was replenished during August and September. Little change in water content occurred overwinter. This study suggests that no tillage favors barley production only in dry years by conserving soil water. However, unlike other tillage treatments, grass weed infestations in no tillage prohibited the continuous production of barley in interior Alaska.