Effects of irrigation and planting geometry on cotton productivity and water use efficiency

Authors: PINNAMANENI, SRINIVASA - Oak Ridge Institute For Science And Education (ORISE); Anapalli, Saseendran; Reddy, Krishna; Fisher, Daniel

Submitted to: Journal of Cotton Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/3/2020
Publication Date: 11/8/2020
Citation: Pinnamaneni, S.R., Anapalli, S.S., Reddy, K.N., Fisher, D.K. 2020. Effects of irrigation and planting geometry on cotton productivity and water use efficiency. Journal of Cotton Science. 24(2):87-96.

Interpretive Summary: The Mississippi (MS) River Valley Alluvial aquifer has started declining sharply in recent years due to irrigation water withdrawals incommensurate to their recharge levels, threatening the sustainability of irrigated agriculture in the MS delta region. In order to reduce further loss of this aquifer water resource, crop-irrigation practices need to be an efficient one while enhancing farm productivity and profitability. To address this, scientists with the USDA ARS Sustainable Water Management Research Unit and Crop Production Systems Research Unit, Stoneville, MS, conducted an experiment by varying planting geometry and following three irrigation regimes in the Lower MS Delta, USA during 2018-19. The results of the study indicated a 14 % yield advantage in cotton lint production by adopting a twin-row production system while alternate row irrigation reduced water use for irrigation significantly without any yield reduction in comparison with all-row irrigation. This study is expected to help cotton producers to use water efficiently as well as optimize lint yield while sustaining the limited ground water resources in the aquifer using sustainable water management practices that promote water conservation.

Technical Abstract: Mississippi (MS) River Valley Alluvial aquifer has started declining in recent years due to irrigation water withdrawals incommensurate with their recharge levels, threatening the sustainability of irrigated agriculture in the MS delta region. In a two-year study (2018 and 2019), we examined the effects of different levels of irrigations and planting geometries on lint yield and WUE of furrow irrigated cotton (Gossypium hirsutum L.) on a Dundee silt loam soil in the lower Mississippi (MS) Delta, USA in a warm and humid climate. The main plots were three irrigation regimes, irrigating every furrow (FI, full irrigation) and alternate furrow (HI, half irrigation), and no irrigation (RF, rainfed), and subplots were two planting geometries, single-row (SR) and twin-row (TR). Averaged across the three irrigation regimes, compared to SR, the TR planting enhanced lint yield by 10.62% in 2018 and 17.62% in 2019. The average lint yield in SR and TR planting geometries were, 1779 and 2028 kg ha-1 under FI, 1803 and 2082 kg ha-1 under HI, and 1573 and 1788 kg ha-1 under RF treatments, respectively. In FI and HI treatments, TR planting geometry had higher lint yield than RF treatment by 13.46% and 16.43%, respectively. Lint yield harvested in HI and TR combination had the highest irrigation WUE (3.4 kg ha-1 mm-1) followed by the HI and SR (2.7 kg ha-1 mm-1). These results demonstrated that cotton grown in the TR planting geometry combined with HI irrigation strategy can significantly reduce water demand for irrigations while enhancing productivity.