Method for rapidly diagnosing nitrogen nutrition in oilseed rape leaves and recommending application of nitrogen

Abstract

The invention relates to a method for rapidly diagnosing nitrogen nutrition in oilseed rape leaves and recommending application of nitrogen. The method is characterized by comprising the following steps: (1) measuring an SPAD (soil and plant analyzer development) value of the oilseed rape leaves; (2) determining an SPAD critical value of the oilseed rape leaves and predicting the yield of oilseed rape, namely measuring the yield of oilseed rape under different nitrogen application levels after harvesting oilseed rapes, and establishing a linear application platform model according to the yield of oilseed rape and the SPAD value, wherein the SPAD value corresponding to a platform corner in the model is the SPAD critical value of the oilseed rape leaves, and a linear equation in the model is used for predicting the yield of oilseed rape; and (3) establishing a oilseed rape nitrogen application recommendation model, namely establishing another linear application platform model according to the yield of oilseed rape in the step (2) and a nitrogen application rate to obtain a relation equation of a nitrogen fertilizer dosage at the platform corner, a base fertilizer nitrogen application rate and the yield of oilseed rape, and reducing the base fertilizer nitrogen application rate by the nitrogen fertilizer dosage at the platform corner to obtain the dosage of nitrogen in a fertilizer applied to oilseed rape in a land to be detected. The method for diagnosing nitrogen nutrition in oilseed rape and recommending a nitrogen fertilizer application rate is simple in process, high in reliability and low in cost.

Description

technical field [0001] The invention belongs to the field of agriculture, and in particular relates to a method for quickly diagnosing the nitrogen nutrition of rapeseed leaves and recommending nitrogen topping. Background technique [0002] Rapeseed is the most important oil crop in my country, accounting for more than 40% of domestic edible vegetable oil supply, and can provide more than 7 million tons of high-quality protein feed for animal husbandry every year. However, my country's rapeseed material input, especially fertilizer input costs are high (accounting for more than 50% of the total material cost), and the fertilizer utilization rate is low (the apparent utilization rate of nitrogen fertilizer is 30% to 35%, only half of that of developed countries), which reduces the The economic benefits and enthusiasm of farmers in rapeseed planting. [0003] Nitrogen fertilizer is the most widely used chemical fertilizer in the world, and it is also the most difficult fertil...

AI Technical Summary

Problems solved by technology

In addition to being affected by the physical and chemical properties of nitrogen itself, the lack of accurate, rapid and economical methods for judging the nitrogen nutrition status of crops and recommending fertilization is also an important factor

For a long time, the nitrogen nutrition diagnosis and recommended application of crops are based on routine laboratory tests, which require a lot of manpower and material resources in sampling, preparation, measurement, data analysis, etc., and the timeliness is poor, which is not conducive to popularization and application; some qualitative Or semi-quantitative methods, such as the fertilizer window method, etc., cannot effectively quantify the amount of fertilizer required by crops

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