水稻钵苗机插秧苗素质的调控

摘要

Rice potted-seedling of mechanical transplanting, which adopt a new type of transplanter with a certain line of planting distance, is a major technological innovation on rice production. In recent years, the technology has increased production significantly in Jiangsu, Heilongjiang, Anhui, and Jiangxi, etc. In order to promote the technology, Yangzhou University has been conducting research on rice potted-seedling in mechanical transplanting, with several units cooperating. This paper selected Wuyunjing24 as experimental material to investigate the effects of seedling quality caused by different sowing densities, irrigation management and twice chemical regulations of rice potted-seedlings in mechanical transplanting. The results indicated:1) as the number increased, the quality of potted-seedings tended to be inferior;it was mainly reflected in the delicate seedlings, the reduction of dry weight, poor plumpness, poor root development, et al. High sowing density consumed a large number of seeds, so the seedling populations received restrictive ventilation and light, and also the competition among the individual plants became intense in each bowl of the nursing tray, and those resulted in poor quality which was not conducive to high yield. Seedlings of a low sowing density had enough space to absorb nutrition, and the seedling quality was optimized. The soil in the potted-tray, however, would have intensive lumpy forms in low probability, which was difficult to cooperate with the rice transplanter. Besides, the thin planting and high leakage rate made it hard to meet the requirements of high yield. The suitable sowing amount of the normal japonica rice, Wuyunjing24, with a large fringe, was 45-60 g in each potted tray, and on average, there were 3-4 strains of plants per plastic hole. 2) Regarding the water management, the dry rice seedling had more tiller and higher chlorophyll content than the seedlings in the moist environment. Dry management delayed the stagnant growth period of tiller, and the degradation rate of chlorophyll was low, which improved the seedlings’ ability to maintain green. Under the experimental conditions, the seedling ages could be extended to 35 days. 3) Twice chemical regulations, by analyzing the seedling plumpness through the orthogonal design of seedling-strengthening agent, MET, water management, sowing densities, was determined as the optimal combination. Timely and appropriate twice chemical regulations could approve seedling plumpness and quality significantly, and it could achieve the uniformity of seedlings in height. To achieve seedling of the best quality, the optimal method was that in the condition of 45 g per potted tray under dry management, mixing up 100 kg subsoil with a 0.5 kg seedling-strengthening agent, and spraying 0.06g MET per tray in the two-leaf period.%为探讨适宜水稻钵苗机插培育壮秧新技术，促进技术大面积推广应用。该文以武运粳24号为材料，研究了钵苗机插稻育秧中的播种量、秧田水分管理及二次化控组合施用对秧苗素质的影响。结果表明：1）播种量试验中，钵苗的秧苗素质随播量的增加而趋劣。高播量处理秧苗群体通风透光受限，穴钵内个体竞争激烈，秧苗素质较差；低播量处理苗质各性状得到优化，但钵体成球度差，难以配套插秧机田间正常栽插作业，且基本苗偏少、漏插率高。偏大穗型常规粳稻品种武运粳24号适宜的播量为45～60 g/盘，平均每孔成苗3～4株。2）秧田水分管理下，旱育钵苗群体带蘖率和叶片叶绿素含量较湿润秧有一定优势。旱育方式推迟水稻群体茎蘖滞增期，叶片叶绿素降解率低、持绿能力较强，该试验条件下适栽秧龄可延长至35 d。3）二次化学调控中，通过多因子正交试验对秧苗充实度进行分析，确定了二次化控最优组合。表明适量、适时二次化控可显著提高秧苗素质，有效控制苗高，增加秧苗整齐度。在具体调控措施上，认为播量45 g/盘、旱育方式下，每100 kg底土拌入0.5 kg壮秧剂，2叶期每盘施多效唑0.06 g，钵苗秧苗素质表现最佳。该研究可为水稻钵苗机插培育壮秧提供技术参考。