|Evett, Steven - Steve|
Submitted to: Transactions of the ASAE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/3/1997
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 study 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, 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 fone day or seven days on the Pullman soil. Irrigation amount did affect crop field by decreasing both kernel weight and numbers of kernels per ear of corn.
Technical Abstract: Microirrigation has the potential to minimize application losses to evaporation, field runoff, and deep percolation; improve irrigation control with smaller, frequent applications; supply nutrients to the crop as needed; and improve crop yields. This study was conducted to evaluate subsurface and surface microirrigation (SUB and TOP, respectively) 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., cv. PIO 3245) were investigated at Bushland, TX, on a slowly permeable soil [Pullman clay loam (fine, mixed, thermic Torrertic Paleustoll)] in a semi-arid environment in 1993 and 1994. 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 (TOP) and below the ground (0.3 m; SUB) with emitters spaced 0.45 m apart and drip lines spaced 1.5 m apart. Irrigation frequency and application method did not affect crop yields; however, deficit 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 corn yield for microirrigation systems.