不同栽植方式下杂交中稻分蘖期田间适宜蓄水深度研究

【目的】湖北平原湖区6—7月降雨较多,因此,需合理利用降雨资源,确定雨后田间适宜蓄水深度。【方法】结合湖北平原湖区生产实际,针对中稻机插秧和直播2种播种方式,在中稻分蘖期进行了不同蓄水深度(4、8、12和16cm)测坑试验。【结果】当模拟机插稻蓄水深度4 cm、直播稻蓄水深度8 cm时,水稻叶片的光合速率最高,10～20 cm土层的根系干质量最大,产量最高;对模拟机插稻,蓄水深度8、12、16 cm的处理,产量较4 cm处理分别降低3.75%、9.49%和11.97%;对直播稻,蓄水深度4、12、16 cm的处理,其产量较8 cm处理分别降低5.03%、12.87%和16.45%。【结论】在本试验所研究的蓄水深度下,模拟机插稻与直播稻在分蘖期适宜的蓄水深度分别为4 cm和8 cm。当遭遇大暴雨导致农田排水不畅时,在允许水稻减产12%左右的情况下,分蘖期机插稻蓄水上限为16 cm,直播稻蓄水上限为12 cm。

Rational Water Storage Depth in the Paddy Field during Tillering Stage of Mid-season Hybrid Rice in Different Cultivation Ways

【Objective】There are more rainfalls in the plain lake area of Hubei from June to July, and it is very important to make reasonable use of rainfall resources to determine water storage depth(WSD) in the field after raining.【Method】Combined with the actual production of the lake plain in Hubei Plain, the pit test of different water storage depths(4 cm, 8 cm, 12 cm and 16 cm) was carried out in the middle rice tillering stage for the simulating machine transplanting rice(SMTR) and the direct seeding rice(DSR).【Result】Under the water storage depth studied in this experiment, when the SMTR depth was 4 cm and the DSR depth was 8 cm, the photosynthetic rate of rice leaves was the highest, the SPAD value was the largest, and the dry weight of roots was the highest in 10～20 cm soil layer, the highest yield. The grain yield of SMTR under the treatments of WSD in 8 cm, 12 cm and 16 cm reduce by separately 3.75%, 9.49% and 11.97%; for direct seeding rice, the grain yield of treatments of WSD in 4 cm, 12 cm and 16 cm reduce by separately 5.03%, 12.87% and 16.45% with contrast to the treatment of WSD in 8 cm.【Conclusion】Under the water storage depth studied in this experiment, suitable water storage depth was 4 cm for SMTR and 8 cm for DSR. When the poor drainage of the farmland caused by the heavy rain in tillering stage, the maximum water storage limit of the SMTR was 16 cm, and the upper limit of the WSD storage capacity was 12 cm.