Effect Of Area-formula Fertilizer On Double-cropping Rice And Mechanism Research

In this paper, a field plot experiment was conducted to investigate the effect of six treatments on double-cropping rice growth, nutrient utilization characteristics, rice yield as well as economic benefit. The six treatments included no fertilizer(T1), no nitrogen(T2), farmer’s conventional fertilization(T3), area-gross formula(T4), area-gross formula+minor-adjustment1(T5) and area-gross formula+minor-adjustment2(T6). The primary results were as follows:1、Plant height of double-cropping rice varied with different fertilization level. Early rice plant height in treatments of area-gross formula and farmer’s conventional fertilization ranked the highest levels in Xiangyin and Heshan regions; Late rice plant height in farmer’s conventional fertilization was the highest, and that in area-gross formula treatment ranked the second place in two regions. Results of rice tillering index in two districts showed that T3and T4were favorable for tillering emergence of double-cropping rice at early tillering stage, and T4was more helpful to improve effective tillering than T3.2、SPAD value of rice leaf in normal fertilization treatments (T3-T6) kept high levels and was significantly different with that in T1and T2(P<0.01). Chlorophyll content of each treatment ranked high level at tillering and pustulation stages, but declined at yellow ripening stage. Except the result in Heshan region at tillering stage in late rice, chlorophyll content was not significantly different among normal fertilization treatments. The SPAD value in T5and T6were obviously lower than that in treatments of farmer’s conventional fertilization as well as area-gross formula, but the SPAD value between T3and T4was not significantly different.3、Starch content in top leaf sheath was small and less affected by fertilizer application level at yellow ripening stage of rice. Among of them, the starch content of top leaf sheath in early rice varied in8.5%-11.4%、9.1%-11.6%, and that in late rice varied in9%-14.4%、7%-9.1%in two regions, respectively. Except the top leaf sheath, starch content in other leaf sheaths in T1and T2was higher, while starch content in normal fertilization treatments was not obviously distinct.4、Aboveground dry material accumulation and nutrient uptake can be improved when N, P and K fertilizer application level and the ratio are proper. Experiment in Xiangyin showed that compared to T3treatment, N and P accumulation of aboveground part in T4treatment improved by9.46%,14.82%at harvest stage of early rice, and the N, P and K use efficiency in T4treatment improved by5.12%、10.61%and8.55%, respectively; As to late rice, compared to T3, N, P and K accumulation in T4improved by11.68%,55.01%,15.94%at harvest stage, and the N, P and K use efficiency improved by5.6%,36.7%and1.48%, respectively. Results in Heshan demonstrated that in contrast to T3, agronomic efficiency of N, P and K in T4enhanced by25.05%,47.26%and61.12%, and PFP of N, P and K increased by10.26%,10.3%and65.39%, respectively.5、Area-formula treatment is favorable to increase effective panicle number, filled grains as well as seed-setting rate, thus improving rice grain yield, decreasing fertilizer input, as a result of enhancement of yield and efficiency in rice cultivation eventually. Results in Xiangyin demonstrated that early rice yield in T3and T4ranked high level, and there was no significant difference between them; In contrast to T3, late rice yield in T4increased by4.6%; The input-output ratio of T4in early and late rice amounted to2.24and2.74, respectively, and the net profit of double-cropping rice was1444yuan/hm. Results in Heshan region showed that rice yield in T4was10.3%higher than that in T3, and compared to T3, late rice yield in T4increased by1.71%; The input-output ratio of T4in early and late rice was2.47and1.9, respectively. Meanwhile, the net profit of double-cropping rice was3529yuan/hm2.Taken together, area-gross formula treatment, which decreases K fertilizer application level properly in early rice and declines N and K fertilizer application level in late rice on the basis of farmer’s conventional fertilization treatment, is advisable in rice cultivation in Xiangyin and Heshan regions.