钵苗摆栽籼粳杂交稻和常规粳稻丰产优质适宜施氮量分析

研究钵苗摆栽下籼粳杂交稻、常规粳稻丰产优质施氮量及综合效益,提出安徽沿江地区钵苗摆栽下适宜粳稻类型及施氮量。于2016—2017年连续2 a开展大田试验,以当地主栽籼粳杂交稻甬优1540和常规粳稻镇稻18为供试品种,设置0、195、255、315、375 kg/hm~2共5个氮肥水平(分别用N0、N195、N255、N315、N375表示),研究不同施氮水平对钵苗摆栽下不同类型粳稻产量、品质、相关农艺性状及经济效益的影响。结果表明,籼粳杂交稻甬优15402a均在N315处理下产量最高,达到10.30～11.55t/hm~2。常规粳稻镇稻18各施氮处理下水稻产量无显著差异,产量为7.43～8.91 t/hm~2。增施氮肥,不同程度增加了2个品种的糙米率、精米率和蛋白质含量,提高了加工品质和营养品质,但垩白率和垩白度整体有所提高,直链淀粉含量增高,不利于外观品质和食味的改善。甬优1540在N315处理下的整精米率与N375无差异,且在N315处理下的垩白度与N195无显著差异。另外,镇稻18在N195处理下的整精米率、蛋白质含量、垩白度和直链淀粉含量与其他氮肥处理无显著差异。钵苗摆栽下籼粳杂交稻丰产优质施氮量为315kg/hm~2,常规粳稻为195 kg/hm~2。在适氮水平下,钵苗摆栽甬优1540较镇稻18提高水稻产量22.9%～23.2%,整精米率2.15%～4.50%,蛋白质含量30.44%～37.41%,经济效益51.07%～53.33%,同时降低垩白度9.52%～13.73%。总的来说,在适宜氮肥水平下,钵苗摆栽下籼粳杂交稻较常规粳稻提高了水稻产量、品质和经济效益。

Appropriate fertilizer-N application rate for high yield and premium quality of pot-seedling transplanted indica-japonica hybrid rice and conventional japonica rice

Abstract: Compared with conventional japonica rice, the grain yield of indica-japonica hybrid rice in pot-seedling transplanting is more advantageous. However, there are few studies on its quality effect under high nitrogen application rate. A field experiment was performed to investigate the effects of five fertilizer-N application rates (0, 195, 255, 315, 375 kg/hm2 represented by N0, N195, N255, N315, N375) on grain yield, rice quality, agronomic traits and economic benefit of Yongyou1540 (indica-japonica hybrid rice) and Zhendao18 (conventional japonica rice), which are local main cultivars, in 2016 and 2017. Due to increase in leaf area index and net photosynthetic rate after the panicle initiation, dry matter accumulation, increase in the number of spikelets per panicle, the filled grain rate and thousand-grain weight were ensured, the grain yield of Yongyou1540 under N315 was the highest at 11.55 t/hm2 (2016) and 10.30 t/hm2 (2017). Compared to the other N treatments, N315 increased the yield by 0.98%-8.35%. No significant difference was found for rice yield of conventional japonica rice Zhendao18 among different nitrogen application rates, with grain yield of 8.49-8.91 t/hm2 and 7.43-7.91 t/hm2 in 2016 and 2017. When the nitrogen application rate was less than 315 kg/hm2, the dry matter accumulation at the maturity stage and leaf area index at the heading stage of Yongyou1540 increased with the increase of nitrogen application rate. When the nitrogen application rate exceeded 315 kg/hm2, it continued to increase and even has a downward trend. Increased application of nitrogen fertilizer improved the milling quality by increasing the brown rice rate, milled rice rate, and improved nutritional quality by increasing the protein content of the two varieties. However, the chalkiness and chalkiness degree increased and the amylose content decreased. The head rice rate of Yonyou1540 under N315 was 74.17% and 69.97% in 2016 and 2017, and they were not significantly different from N375. The chalkiness (11.00%, 17.33%) under N315 had no significant difference with N195. In addition, the percentage of head rice, protein content, chalkiness and amylose content of Zhendao18 under N195 was not significantly different from the other nitrogen fertilizer treatments. As the amount of nitrogen applied increased, the net income of Yongyou 1540 showed a trend of increasing and then decreasing, and N315 was the largest (15 513.3 and 12 263.3 Yuan/hm2 in 2016 and 2017). However, the income-increasing benefit of Zhendao 18 was not obvious by increasing application of nitrogen fertilizer. The amount of nitrogen fertilizer with high-yield and premium-quality of indica-japonica hybrid rice in pot-seedling transplanting was 315 kg/hm2, and that of conventional japonica rice was 195 kg/hm2. Compared to Zhendao18, Yongyou1540 in pot-seedling transplanting under suitable nitrogen levels improved grain yield by 22.9%-23.2%, increased head rice rate by 2.15%-4.50%, increased protein content by 30.44%-37.41%, and increased economic benefits by 51.07%-53.33% while reduced chalkiness by 9.52%-13.73%. In general, it is conducive to improving rice yield, quality and economic benefits for selecting indica-japonica hybrid rice in pot-seedling transplanting under 315 kg/hm2 nitrogen fertilizer along the Yangtze River area in Anhui Province.