浅层施肥对水稻苗期养分吸收及土壤养分分布的影响

采用盆栽土柱试验研究不同施肥深度对水稻秧苗生物量、养分吸收及土壤养分分布的影响,以期为水稻育秧合理施肥提供理论依据。结果表明:播种后10天,各处理水稻生物量无显著差异;播种后20天,施肥深度1 cm处理生物量与其他处理相比平均显著增加80.6%;播种后40天,施肥深度1 cm和5 cm处理与10 cm处理相比分别显著增加70.9%和30.7%。养分吸收结果与生物量表现一致,播种后20天,施肥深度1 cm处理秧苗氮、磷、钾素吸收量分别平均提高86.9%、156.9%和202.7%;播种后40天,施肥深度1 cm和5 cm处理与10 cm处理相比分别增加52.3%和24.8%、23.8%和20.4%、50.5%和43.1%。随着生育进程的推进,土壤有效养分含量均逐渐下降,且有向下迁移的趋势;其中施肥深度1 cm和5 cm处理0~10 cm土层中无机氮、速效磷、速效钾含量显著高于其他处理。适宜的浅层施肥明显促进水稻秧苗的生长发育,浅层施肥方式施入的速效养分主要集中于土壤上层,利于秧苗生长对养分的吸收,提高秧苗养分含量,增加养分吸收量,有利于提高养分资源利用效率。

Effects of Shallow Fertilization on Rice Nutrient Uptake and Soil Nutrient Distribution at Seedling Stage

The effect of different fertilization depth on biomass, nutrition absorbing of rice and distribution of soil nutrition on the conditions of potting soil column experiments were studied, with a view to provide information for rice seedling rational fertilization. The results showed that biomasses had no significant differences among treatments at 10 d after sowing. That of 1 cm treatment was 80.6% higher than others at 20 d after sowing. The treatments of 1 cm and 5 cm were 70.9% and 30.7% higher than 10 cm at 40 d after sowing, respectively. The same rule showed between nutrient uptake and biomass. Compared with the 10 cm, N, P₂O₅ and K₂O absorbing amounts of 1 cm and 5 cm were increased by 52.3% and 24.8%, 23.8% and 20.4%, 50.5%and 43.1% respectively. The available nutrient content decreased in the soil with root absorbing nutrient, and available nutrient in the soil permeated downwardly with water. Inorganic nitrogen, available phosphorus and potassium content of 1 cm and 5 cm showed significantly higher than others in 0 ~ 10 cm soil layer. The method of appropriate fertilizer in shallow soils kept available nutrients mainly concentrated in the upper soil. In the early rice growth period, the fertilization method could promote rice seedling growth, increase nutrient absorption, and improve the nutrient status in seedling field.