Abstract:

A field experiment was carried out from June to November 2021 in tidal flat of Nantong, Jiangsu Province to study the effects of different exogenous silicon fertilizers spraying on rice yield, dry matter and nutrient accumulation and transport in various organs and rice quality, with ‘Nanjing 5055’ as the test variety. Five treatments were set up in the experiment, including spraying water treatment (CK), sugar alcohol silicon treatment (SF₁), seaweed liquid silicon treatment (SF₂), liquid silica-zinc fertilizer treatment (SF₃) and highly active ionic liquid silicon treatment (SF₄). The results showed that (1) compared with CK, rice yield under SF₁, SF₂, SF₃ and SF₄ increased by 9.24%, 7.31%, 0.28% and 3.64%, respectively, and reached a significant level under SF₁. At the same time, the number of grains per panicle, the number of solid grains, the weight of thousand grains, the length of panicle and the density of grains were increased significantly under SF₁ (P<0.05). (2) The above ground dry matter accumulation of rice at maturity was SF₁>SF₂>SF₄>SF₃>CK. At heading stage, nitrogen accumulation in the above-ground part and potassium accumulation in the upper part of the ground under SF₁ and SF₃ were significantly increased under each spraying treatment. Nitrogen accumulation in the lower panicle and above-ground parts of SF₁, SF₃ and SF₄ at maturity was significantly increased (P<0.05). The distribution of nitrogen and potassium accumulation in each organ of rice at heading stage was in the order of stem sheath>leaf>ear. The distribution of nitrogen accumulation at maturity was in the order of spike>sheath>leaf, and the distribution of potassium accumulation was in the order of sheath>ear>leaf. (3) Compared with CK, leaf dry matter transfer (SF₃) and ear dry matter increase (SF₁, SF₂ and SF₃) were significantly increased. Nitrogen transfer in stem sheath (SF₂, SF₃ and SF₄) and leaves (SF₁) and nitrogen increase in panicle (SF₁, SF₃ and SF₄) were significantly increased. The transfer volume of potassium in stem sheath (SF₃) and leaf (SF₁) and the increase of potassium in panicle (SF₃) were significantly increased (P<0.05). (4) Rice yield was positively correlated with spike dry matter increase and nitrogen transfer, significantly positively correlated with dry matter accumulation and spike nitrogen accumulation at maturity, and significantly negatively correlated with leaf potassium accumulation. (5) Different exogenous silicon fertilizers spraying had no significant effects on the appearance and processing quality of shoal rice under the experimental conditions. Therefore, spraying appropriate exogenous silicon fertilizer (especially sugar alcohol silicon) on the leaf surface could significantly increase rice yield in this coastal mudflat area. Spraying exogenous silicon fertilizer mainly improves the number of grains per spike and the quality of 1000 grains, increasing the accumulation of dry matter and nitrogen in the rice spike.

Key words: foliar silicon fertilizer, tidal flat rice, saline-alkali land utilization, nitrogen accumulation, potassium accumulation