机械旱直播方式对水稻氮磷钾吸收转运及分配的影响.

In order to clarify the nutrient utilization characteristics of mechanical dry direct-sowing rice, the objective of this experiment was to study the effects of different mechanical dry direct-sowing modes on absorption, translocation and distribution of nitrogen (N), phosphorus (P), potassium (K), and yield in rice. Two rice cultivars of indica hybrid rice F you 498(143 days growth duration) and conventional japonica rice Xudao 4 (145 days growth duration) were planted with two mechanical dry direct-sowing modes, including no-tillage land and mechanic drilling simultaneously (B1), regulating soil moisture and two rotary tillage before mechanic drilling (B2). Manual broad-cast sowing (B3) was set as control. The dry direct-sowing machine of this study was modified by Nanjing Agricultural University and was re-modified by Sichuan Agricultural University. This machine had 6 drills and sowing depth 2.0 cm, drill spacing 28.0 cm, working width 1.50 m. Motive power of this machine was the Shanghai New Holland tractor (SNH504). This test adopted row spacing 20.0 m × 1.50 m, each plot covered 30 m2 of seeding amount was 30.0 kg per hectare of indica hybrid rice F you 498, 37.5 kg per hectare of conventional japonica rice Xudao 4 respectively. The nitrogen fertilizer amount was 180 kg/hm2. The N application ratios was applied on 4 splits: 50% basal, 30% tillering fertilizer at 3rd leaf stage, 10% panicle N-fertilizer at 4th leaves emerged from the top, 10% ear granular fertilizer at full heading stage. The phosphate fertilizer application was only one base fertilizer. The potash fertilizer application ratio of basic fertilizer, tillering fertilizer and ear granular fertilizer was 2:1:1. The other management measures were at a uniform with high-yield cultivation. The results showed that there was an obvious regulatory effect of rice cultivars and direct-sowing modes on grain yield, absorption and translocation of N, K at the mainly growth stages. There existed significantly positive correlations between the amounts of N, P and K absorption and utilization, which could promote nutrient translocation during filling stage and yield, but the correlation coefficient of P and N, P and K significantly decreased at the mainly growth stages. Under different direct-sowing treatments, the various indicators on yield and nutrient utilization characteristics of F you 498 were significantly higher than those of Xudao 4. Compared with B3 treatment, mechanical direct-seeding treatments under the same variety promoted the accumulations of N, P, and K at the mainly growth stages, increased nutrient translocation in leaf and stem-sheath during filling stage, especially significantly enhanced transportation efficiency of N and K in hybrid rice, and further facilitated translocation conversion rate of N and K in different vegetative organ, played the coupling effect of absorption and utilization of N and K, then to promoted yield, which is the important reason for mechanical direct-sowing rice further to increase yield. Under different mechanical direct-sowing treatments, compared with B1, B2 treatment was the best model in this paper referred as the mechanical direct-sowing treatments, which could further increase nutrient accumulation and translocation from heading to maturity stage in various degrees consequently, promote nutrient accumulation in panicle as well as promote yield. [ABSTRACT FROM AUTHOR]