Laserfiche WebLink
<br />Farm D8 - <br /> <br />l\) <br />CD <br />0) <br />C.::> <br /> <br />Farm D9 - <br /> <br />The demonstration plot in this farm is a six acre <br />field of alfalfa hay. The soil is billings silty <br />clay with variable slope. Part of the field has <br />a hard pan, making water penetration a slow <br />process. Over watering occurs in the rest of the <br />field by the time water soaks in the problem area. <br />The owner has two different pipe sizes - 8" at the <br />beginning and changes to 6" on the other side of <br />the valve where it rises uphill. This causes <br />differential water flow between sets. At present <br />the ditch water.is put into the gated pipe at a <br />point where the head differential is very low. <br /> <br />The problem has been explained and the owner plans <br />to buy enough 8" gated pipe and some length of <br />conveyance pipe to move uphill at a higher <br />elevation point in the ditch to secure enough <br />water head pressure. <br /> <br />The demonstration set up established in this farm <br />was a twenty acre plot of corn. An in-line valve <br />system was used. The in-line valve used is a <br />proto-type. If found successful the owner will be <br />provided with an appropriate in-line valve to be <br />retained free according to contract. The plot has <br />a hump in the middle making it difficult for the <br />water to run over the rise. The furrows in the <br />low spot tend to break and create crossover. In <br />the first irrigation the canned program could not <br />handle the advance. The advance to the end of the <br />furrow was delayed and soak cycle would start <br />before water reached the end. The situation was <br />overcome by increasing the time for advance cycle. <br />Program #6 or 7 was used where time of advance to <br />one sixth length was little exaggerated. <br /> <br />The owner sometimes had difficulty in appreciating <br />that the field had already received enough water <br />at the end of irrigation. So he would stop the <br />program and run some more water conventionally <br />making data unusable. In few occasions the over <br />irrigation was high and there was tremendous deep <br />percolation, both in conventional and surge. Of <br />course the highest deep percolation always <br />occurred in conventional situation (see Table I). <br />We faced difficulty in running program #6 or #7 - <br />the "waterman" controller would center itself at <br />the end of advance. This is being resolved. <br /> <br />A-J <br />