What is the effect of different fertilizer ratios on rice yield?
When rice shows premature senescence from the heading to the maturity stage, it leads to poor grain filling, an increase in blighted grains, and reduced yield. There are many factors that cause premature senescence in the late growth stage of rice. First, improper cultivation management. If the planting density is too high, the plants grow thin and weak; if too much nitrogen fertilizer is applied in the early and middle stages, while phosphorus, potassium and trace element fertilizers are applied...
Nitrogen is an essential nutrient for plant growth. It is a component of every living cell, a component of chlorophyll, and also a component of the vitamin and energy systems in plants. The content of phosphorus in plants is second only to nitrogen and potassium, and is generally higher in seeds. Phosphorus participates in photosynthesis, respiration, energy storage and transfer, cell division, cell enlargement and other processes in plants. It can promote the formation and growth of the root system in the early stage and improve the ability of plants to adapt to external environmental conditions. Phosphorus can improve the quality of food crops. Potassium is a major nutrient element for plants and is also one of the three essential elements in soil that often affect crop yield due to insufficient supply. Potassium can promote photosynthesis, and it can significantly improve the absorption and utilization of nitrogen by plants. Another characteristic of potassium is that it helps crops resist stress. One of the important physiological roles of potassium is to enhance the ability of cells to regulate environmental conditions and improve plant stress resistance. I. Test materials and methods
The test was set up in 2008 in the rice experimental field of the Science and Technology Park of Hongwei Farm in Heilongjiang Province. The soil type was meadow albic soil, with soil organic matter content of 48.9g/kg, alkaline hydrolyzable nitrogen 172mg/kg, available phosphorus 31.3mg/kg, available potassium 87mg/kg, and pH 6.39. The tested rice variety was Kongyu 131.
The test adopted a large-plot comparison method without replication, and three different fertilizer ratios were set up respectively. A total of 3 treatments were set up in the test. Treatment 1 applied pure N150kg, P2O5150kg, K2O150kg per hectare; Treatment 2 applied pure N165kg, P2O560kg, K2O225kg per hectare; Treatment 3 applied pure N120kg, P2O5150kg, K2O180kg per hectare.
II. Test results and analysis
(I) Growth period investigation
From the growth period investigation results, in terms of heading time, Treatment 1 was July 26, Treatment 2 was July 26, and Treatment 3 was July 25; in terms of maturity stage, Treatment 1 was September 9, Treatment 2 was September 9, and Treatment 3 was September 8. The results showed that Treatment 1 and Treatment 2 had no difference in growth period, and only Treatment 3 was 1d earlier than Treatment 1 and Treatment 2 at each growth stage.
(II) Growth trait investigation
From the investigation results, in terms of the number of tillers in the field, the effective tiller number of Treatment 1 was 30.1 plants/hill, the effective tiller number of Treatment 2 was 28.5 plants/hill, and the effective tiller number of Treatment 3 was 31.3 plants/hill. For diseases, only a small amount of sheath rot occurred. The disease incidence rates of each treatment were: Treatment 1 was 18.6%, Treatment 2 was 15.4%, and Treatment 3 was 15.7%. There was little difference in plant height among the treatments. Only Treatment 2 had the lowest seed setting rate, at 82.5%. Only Treatment 3 showed lodging at the final maturity stage.
The test results showed that as the amount of phosphorus fertilizer decreased, the seed setting rate also decreased; as the amount of potassium fertilizer increased, the disease incidence rate gradually decreased. The change in the amount of nitrogen fertilizer was not large, so the result was not very obvious.
(III) Yield trait investigation
From the test results (see Table 1), among the yield results, the yield of Treatment 1 was 9679.5kg/hm2, Treatment 2 was 9088.5kg/hm2, and Treatment 3 was 9865.5kg/hm2. According to the analysis of milled rice rate, the milled rice rate of Treatment 1 was 68.6%, Treatment 2 was 65.2%, and Treatment 3 was 70.3%.
III. Brief summary
For high-yield cultivation of paddy fields, the fertilizer application rate should be appropriate and the ratio should be reasonable. The fertilizer application rate should be determined according to the fertility of different plots. Combined with soil test results and according to soil fertility conditions, reasonably supplement the nutrient elements lacking in the soil, accumulate nutrients to improve soil fertility, and carry out formula ratio fertilization to ensure high and stable rice yield and improve rice quality. Combined with the test data, the optimal fertilizer application rate for high-yield cultivation of paddy fields is pure N120kg, P2O5150kg, K2O180kg per hectare, with a yield of 9865.5kg/hm2 and a milled rice rate of 70.3%.