Preplant and early-season cotton irrigation timing with deficit amounts using subsurface drip (SDI) systems in the Texas
- PDF / 925,308 Bytes
- 15 Pages / 595.276 x 790.866 pts Page_size
- 53 Downloads / 147 Views
ORIGINAL PAPER
Preplant and early‑season cotton irrigation timing with deficit amounts using subsurface drip (SDI) systems in the Texas High Plains James P. Bordovsky1 Received: 13 August 2019 / Accepted: 19 December 2019 © Springer-Verlag GmbH Germany, part of Springer Nature 2020
Abstract Two major irrigation challenges of cotton producers in the Texas High Plains (THP) include the depletion of the Ogallala Aquifer and the highly evaporative, semi-arid environment during late spring and early summer. A recent cotton experiment using center pivot irrigation at deficit irrigation capacities showed the reduction in seasonal irrigation by 20% with minor yield loss by reducing irrigations during the vegetative period instead of attempting to store soil water during this period of high evaporative losses. Due to its method of delivery, subsurface drip irrigation (SDI) should reduce evaporation losses during the preplant and early-season periods and improve water storage efficiency and crop yield even at low irrigation capacity. Two experiments having different SDI installation designs and irrigation capacities were conducted in adjacent fields on clay loam soils over 4- and 5-year periods. Treatments included levels of preplant (PP) and vegetative (Veg) period irrigations. In both experiments, under seasonal growing conditions ranging from favorable to unfavorable, yields and crop values were only modestly increased by additional PP irrigations above that required for germination. Among treatments with common PP amounts, larger irrigation amounts during the vegetative period did not significantly (p 15% increase in cotton yield over center pivot methods (Bordovsky 2019). SDI installations are estimated to exceed 180,000 ha in the THP (HPWD 2018). Compared to center pivot irrigation, SDI systems should drastically reduce early-season evaporative losses by eliminating soil surface wetting. Based on results from pairs of large weighing lysimeters at Bushland, TX, water losses due to evaporation were reduced by 50–125 mm using SDI compared to sprinkler irrigation (Evett et al. 2019). However, SDI losses can be high due to water movement below the root zone associated with crop stand establishment in dry years (Bordovsky et al. 2012). One method to improve germination and minimize deep percolation losses with SDI is placement of drip laterals under every crop row instead of traditional "alternate furrow" installations. Cotton response for eliminating or reducing early-season SDI irrigations has not been fully explored. The question is whether preplant and early-season subsurface drip irrigations, during high evaporative periods, can be efficiently stored in the soil profile and increase crop yields. Two field scale experiments were conducted with the objective of evaluating combinations of preplant and early-season irrigation quantities with maximum IC limited to 5.1 mm/d using a traditional SDI design (Experiment 1, E1) and maximum IC limited to 3.8 mm/d using SDI installed under every crop row (Experiment 2, E2). Eval
Data Loading...
