Inter‐row Mulch Increase the Water Use Efficiency of Furrow‐Irrigated Maize in an Arid Environment

The effect inter‐row polyethylene mulch on the water use efficiency and crop productivity of furrow‐ and drip‐irrigated maize (Zea mays L.) was evaluated in a field study. In contrast to the traditional ‘on ridge’ mulching, the inter‐row polyethylene mulch was placed in such a way that it could be easily removed for reuse since the row of plants itself was not covered but the furrows were completely covered. Irrigation needs were computed by multiplying the cumulative Class A Pan evaporation between irrigations by a crop coefficient that changed through the growing season. Our results indicate that inter‐row mulching induced earliness under both irrigation treatments. Seventy five percent of canopy density was attained in the mulched treatments contrasting with 45–61 % in the non‐mulched treatments at 34 days after sowing. Throughout the growing period, shoot biomass was significantly higher for the mulched treatments that had as well higher root biomasses. The overall estimated evaporative losses from the non‐mulched treatments were between 37 % and 39 % of the total water applied. The whole gross canopy water use efficiency in the furrow and drip mulched treatments was 64 % and 45 % higher than in the respective non‐mulched treatments. These results indicate that inter‐row polyethylene mulch is an efficient technique by which soil evaporation is reduced and plant productivity increased.