Research On Potential Productivity And Fertilization Of Rice In Cold Area

Rice productive potential and the market supply is an important problem which directly affect the country’s grain policy and farmers’ income. Heilongjiang province is the largest production base of commodity grain in China. With the increase of population, demand of japonica rice is in a state of equilibrium. Identify and develop the productive potential of cold rice in Heilongjiang province is of great significance. Currently, the research of productive potential of rice only focus on some theoretical level, just like ’Radiation production potential’,’light-temperature production potential’,’Climatic production potential’ and ’soil production potential’, etc. But there is less report on the real productive potential which focuses on small area high-yield research field, but no reports on real productive potential of millions of hectares of rice. This article takes Heilongjiang province as an example, using ’Climatic production potential’ as the theoretical level of rice productive potential in cold area, take the reclamation area and typical production of Heilongjiang as reference, in order to obtain the real productive potential of rice in cold area, and make sure the long-term production targets and short-term production targets. And compare with some examples to get the method of per unit yield increasing, and analyze the fertilization factors on contribution rate of per unit yield, to support the technique and route. The results are as follows:1. The rice yield contribution rate of rice in cold area is 27.1% by air temperature increase. The air temperature production potential is to 20000 kg·hm-2. With the air temperature warming, air temperature production potential is increasing gradually, 360.7kg·hm-2 per 10a, the yield level is only 79.2% of climatic production potential, and 12.7～33.1% of air temperature production potential. There is lot of space to improve the per unit yield of rice in theory.2. There is a relative high level on the rice per unit yield in Heilongjiang reclamation area in past 20 years. Take the reclamation area as a reference, per unit yield of rice in cold area on real productive potential is 1985.6kg·hm-2.3. Study on the high-yielding rice research, the production peak is 15000 kg·hm-2, but only 3 times and the total area is less than 2000 m2. Per unit yield of the high-yielding field is 12500kg·hm-2 steadily. So the productive potential is5500 kg·hm-2-4500 kg·hm-2 on the per unit yield which can be as the medium and long term.4. The improvement of rice yield need good varieties and advanced management mode. For variety, the high-yielding rice varieties characterized by average grain number per panicle grain is 97.4-111.1 grains per spike, seed setting rate is more than 84.2%, and thousand seed weight is 25.9 g to 26.2 g. The height of rice is 90.0～107.0 cm, panicle length is 19.70～21.75cm, length of a knot below spike is 29.50～35.80 cm, the 2nd internode length is 22.00～25.25 cm, the 3rd internode length is 12.10～18.00 cm, the 4th internode length is 3.5～4.5cm, flag leaf length is about 22cm, the 2nd flag leaf length is 30.50～38.50cm, the 3rd flag leaf length is 27.00-33.50 cm.5. In the production factors of rice in cold area, the contribution rate of fertilizing amount to rice per unit yield is 41.6%, the contribution rate of amount of machine-cultivated is 38.3%, the contribution rate of technicians is 19.5%, but with the agricultural technicians change job, labor have restrict on increase of rice per unit yield. And with the increase of the chemical, pesticide consumption have negative effects on rice yield.6. Study on the contribution rate of max fertilizing amount showed that, the SPAD value can directly reflect the lack of N element. The threshold value is 40.5～44.0 in tillering stage, fertilizer diagnosis is applying for rice; the threshold value is 41.0～43.1 in full heading stage, foliar fertilizer diagnosis is applying for rice; the threshold value is 35.0～38.5 in mature period, reasonable nitrogen application is determined for rice.7. Within a certain range of nitrogen, group tillering increased with the increase of N application rate increased. Excessive nitrogen reduces the rice grain/leaf, and reduces production. Dry matter accumulation and yield of rice in different growth period were very significant positive correlation. The largest grain nitrogen accumulation in N application rate is 180 kg·hm-2. N application can increases the total N uptake of rice and nitrogen absorption utilization ratio, nitrogen agronomy efficiency, N physiological utilization efficiency, nitrogen dry matter production efficiency, nitrogen partial production efficiency lower. Under the soil condition of test, applied amount of N fertilizer in the 127 kg·hm-2-150 kg·hm-2 can obtain optimal output.8. The accumulation of dry matter can be promoted by N, P, K application. When insufficient in fertilization, the accumulation of dry matter before the full heading stage is more than the accumulation after the full heading stage. Otherwise, the accumulation of dry matter is mainly in the full heading stage. N is the largest important for grain yield than P and K. On the condition without relationship of fertilization interaction, the best N amount is 112.3 kg-hm2-150 kg-hm2, and he best P amount is 46.7 kg·hm2～63.1 kg·hm2.Under the condition of the right amount of N, P, K fertilizer effect between positive effect between each other, so the N:P:K=1-0.42-0.55:0.39-0.50 is more appropriate.9. K, Si, Mg application can increase the ear number per square meter, number of grain per ear, to improve the yield of rice. The suitable amount is K 51.7kg·hm-2～57.9kg·hm-2, Si 66.3kg·hm-2～190kg·hm-2 Mg 24.2 kg·hm-2～25.3 kg·hm-2, respectively.10. Proper use of Si, Mg can increase the rate of brown rice, brown rice whiteness and rough out rate, the rate of white rice, white appearance and cooking and eating quality, and K can improve the highest viscosity, hot viscosity, plasma viscosity, but can’t effectively increase the cooking and eating quality of rice as a whole. Three kinds of fertilizer have no difference on rice grain length, grain width and white rice whiteness.