Planting models and mulching material strategies to reduce bundle sheath cell leakage and improve photosynthetic capacity and maize production in semi-arid climate.

Abstract

Better understanding of soil water storage and photosynthetic regulation of maize production will be useful to develop a water-saving strategy in rain-fed conditions. Therefore, maize crop was grown under the different cultivation practices for analyzed light and CO2-response curves under various mulching strategies during 2017-2018years. Six different treatments were used such as the following: PP, ridges and furrows zone covered with plastic film mulching; PS, ridges covered with plastic film and furrows zone with stalk mulching; PN, ridges covered with plastic film and furrows zone without mulching; TP, conventional flat planting with plastic film mulching; TS, conventional flat planting with stalk mulching; and TN, conventional flat planting without mulching. The PP treatment had considerable effects on rainwater collection, improved SWS, and maize productivity than that of TP treatment. Significantly increase of SWS was observed under the PP treatment as a result photosynthetic capacity (An) improved under light and CO2-response curves, apparent quantum efficiency (α), respiration rate, total chlorophyll ab content, and 13C-photosynthates distribution in different organs. Under the PP and TP treatments, the maize might keep a great photosynthetic capacity at the post-flowering stage through improving An, LAI, soluble protein, Rubisco contents, and grain yield. The CO2 and light-response curves were significantly enhanced at the PP treatment due to higher 13C carbon isotope (Δ‰) and Ci/Ca as a result lower bundle sheath to leakiness of CO2 (ɸ) compared with the rest of all treatments. The results suggested that PP cultivation practice was the best water-saving strategy because it reduced bundle sheath leakiness to CO2 (ɸ); as a result there's a significant improvement in soil water storage, LAI, 13C-photosynthates distribution, photosynthetic capacity parameters, and maize production.