Seedling transplanting and conservation tillage increases water productivity and seed cotton yield

Crop management approaches, specifically tillage and planting patterns, influence crop productivity in the arid and semi-arid areas. A field experiment was carried out to assess the influence of crop establishment methods under different tillage systems on seed cotton (Gossypium hirsutum L.) yield (SCY), irrigation water productivity (IWP), and yield attributes of irrigated cotton under the ecological conditions of the south of Iran during 2017 and 2018. The experimental design was a randomized complete block with split-plot arrangement in three replicates. The planting patterns were cotton transplanting using a semi-automatic transplanter (CTr), and a cotton direct seeding (CDs) as the main plots. The subplots consisted of four tillage systems: chisel plow plus one disk harrow pass (Til.1), chisel plow plus one power harrow pass (Til.2), stubble cultivator plus one disk harrow pass (Til.3), and moldboard plow plus two disk harrow pass (Til.4). On a two-year average, CTr led to a significant reduction (15.4 %) in the amount of applied water for irrigation as compared to CDs. Cotton grown in CTr produced significantly more total number of bolls and larger boll size compared to those grown by the directseeded method in both years (46.7 and 8.5 %, respectively). The maximum seed cotton yield (SCY) and irrigation water productivity (IWP) were observed from the CTr x Til.1 and CTr x Til.3, whereas the minimum yield and irrigation water productivity occurred in the CDs x Til.4 in average of two years. Results of this study suggested that application of CTr in combination with Til.1 could give an optimum seed cotton yield and water productivity compared to individual use of conservation tillage (Til.1 and Til.3) in cotton-cultivated regions of the southern part of Iran and other areas with the similar ecological conditions.