Performance of flood-irrigated rice as affected by residual rice straw1

Abstract

Rice is an economically important and widely consumed cereal that achieves high yields under flood-irrigated cultivation. However, the amount of residual straw from the previous year may influence its growth and yield. This study evaluated the performance of flood-irrigated rice as affected by residual rice straw, in a greenhouse. A completely randomized design, in a 5 x 4 x 2 factorial scheme, with four replications, was used. Treatments were obtained from a combination of five rice straw amounts (0 t ha-1, 5 t ha-1, 10 t ha-1, 20 t ha-1 and 40 t ha-1), four application times (3, 2, 1 and 0 months before sowing) and two straw application methods (on the surface and incorporated into the soil). The number of panicles and shoot dry mass do not increase when residual straw remains on the soil surface. When the straw is incorporated into the soil on the sowing day, the number of panicles and the shoot dry mass increased by 20 % and 14 %, respectively, if compared to when it was added three months before. The addition of residual rice straw on the surface or incorporated into the soil resulted in a higher yield for flood-irrigated rice grains, when compared to the absence of straw. At 40 t ha-1 of residual rice straw, added at three months before sowing, there was a higher mass yield of rice grains, if compared to the lower amounts of straw.

Effects of straw returning on rice growth and yield under water-saving irrigation

“…Many studies have been concerned with the influence of SR on crop growth and yield (Asten et al, 2005;Kaur and Mahal, 2017;Wang et al, 2018). For paddy fields, previous studies have investigated the impact of the amounts, application time, and burial depth of SR on rice (Oryza sativa L.) growth and yield (Beutler et al, 2017;Mi et al, 2018). It has been demonstrated that SR at the rate of < 7.5 t ha -1 can enhance rice plant height, number of tillers, and biomass production in the middle or late growth stages (Thuy et al, 2008;Han et al, 2012).…”