|Howell T A,|
|Schneider A D,|
|Stewart B A, - WTA&M UNIVERSITY|
Submitted to: Microirrigation International Congress Proceedings
Publication Type: Proceedings
Publication Acceptance Date: November 18, 1994
Publication Date: N/A
Interpretive Summary: Microirrigation or drip irrigation is known to be highly efficient but expensive for row crops. We evaluated drip irrigation systems with laterals spaced in alternate furrows both on the ground and buried about 12 in. The alternate furrow placement reduces drip lines by one-half compared to having lines for each crop row. The buried system, called subsurface drip, greatly reduces the annual labor to remove and re-install surface drip lines, but may become plugged due to many reasons. We determined in this first year of operation that it required a large amount of irrigation water for crop germination with both methods. However, seasonal applications were very efficient. Corn yield was very good even with a later than normal planting, but water use and yields were not very different from other efficient, but less expensive methods (center pivots with LEPA for example). We did not find a significant difference between the buried or surface methods or between an irrigation frequency of one da or seven days on the Pullman soil. Irrigation amount did affect crop yield by decreasing both kernel weight and numbers of kernels per ear of corn.
Technical Abstract: Microirrigation has the potential to minimize application losses from droplet evaporation and drift from sprinklers, improve irrigation control with smaller, frequent applications, supply nutrients to the crop as needed, minimize deep percolation, and improve crop yields. This study was conducted to evaluate subsurface and surface microirrigation application methods on crop performance. The effects of irrigation frequency, amount, and application method on crop yield, yield components, water use, and water use efficiency of corn (Zea mays L.) were investigated in 1993 at Bushland, TX, on a slowly permeable soil [Pullman clay loam (fine, mixed, thermic Torrertic Paleustoll)] in a semi-arid environment. Irrigation frequencies were once a day and once a week; irrigation levels varied from dryland (no post emergence irrigation) to full crop water use replenishment; and application methods were on the soil surface and below ground (0.3 m depth) with emitters spaced 0.45 m apart and drip lines spaced 1.5 m apart. In 1993, irrigation frequency and application method did not affect crop yields; however, severe deficit irrigation (33% of full irrigation) affected crop yields by reducing the seed mass and the seed number. On the clay loam soil at Bushland, irrigation frequency and application method are less critical than proper irrigation management to avoid water deficits that affect crop yield for microirrigation systems.