秸秆还田与化肥减施对水稻生长指标及光合参数的影响

针对水稻生产中存在秸秆处理不当以及化肥用量增多等问题,以山东省济宁市稻麦轮作体系下水稻“圣稻18号”为研究对象,通过田间试验设置3个处理:常规施肥,小麦秸秆不还田(CK);常规施肥+小麦秸秆全量还田(T1);常规施肥量的85%+小麦秸秆全量还田(T2),深入探究秸秆还田与化肥减施对不同生育期水稻生长、光合参数和产量的影响,为制定合理的水稻种植措施提供理论依据。结果表明,稻麦轮作体系下秸秆还田不利水稻前期生长,但能显著提高水稻生长中、后期的生长指标,并增强水稻生长中、后期对氮、磷、钾等养分的吸收。水稻生长中后期T2处理的叶绿素含量、净光合速率以及光谱反射率均为最高,其中灌浆期SPAD值与净光合速率分别较CK处理升高4.4%和37.5%;另外,T2处理生长后期的Fv/Fm、PIabs均较前期所升高。试验还表明,T2处理水稻产量最高,比CK处理增产13.1%,增产的直接原因是单位面积有效穗数的增加。综上所述,秸秆还田配合化肥减施有助于水稻栽培生产中实现高产增效,在实际生产中值得推广应用。

Effects of Straw Returning and Chemical Fertilizer Reduction on Growth Index and Photosynthetic Parameters of Rice

In view of the problems of improper straw treatment and increased fertilizer application in rice production, taking Saint Rice 18 under the rice-wheat rotation system in Jining City, Shandong Province as the research object, three treatments were set up through field experiments:conventional fertilization, wheat straw non-return (CK); conventional fertilization + wheat straw full return (T1); 85% of the conventional fertilization + wheat straw full return (T2). The rice growth, photosynthetic parameters and yield at different growth stages were studied to provide theoretical basis for working out the reasonable rice planting measures. The results indicated that straw returning to field under rice-wheat rotation system was adverse to the early growth of rice, however, it could significantly improve rice growth in the middle and late growth stages, and enhance the absorption of nitrogen, phosphorus, potassium and other nutrients in the middle and late growth stages. The chlorophyll content, net photosynthetic rate and spectral reflectance of T2 were the highest in the middle and late growth stages, and the SPAD value and net photosynthetic rate increased by 4.4% and 37.5%, respectively, compared with CK. During the filling stage, both F_v/F_m and PI_abs were higher than the previous periods. The experiment also showed that T2 had the highest yield, which increased by 13.1% compared with CK. The direct reason for yield increasing was the increase of effective panicle per unit area. In summary, straw returning to the field combined with fertilizer reduction is helpful to achieve high yield and efficiency in rice cultivation production, which is worth popularizing and applying.