Sampling standard in soil testing formula

Sampling standard in soil testing formula

The construction of the evaluation index system is an important part of the soil testing and fertilizer application system, and is the main method for screening and verifying soil nutrient testing methods.
In order to reduce the impact of soil nutrient test system errors on the test results, the county-level laboratories should conduct concentrated tests on the soil under the field test in the same environment and simultaneously determine the standard or reference soil samples; provincial laboratories should conduct field tests in the province After the basic soil is collected, the laboratory with good selection conditions and accurate measurement results is tested in the same environment and compared with the county-level results so that the problems in the soil nutrient testing can be discovered as soon as possible and the county can be guided. Laboratory soil nutrient measurement work.
1. Sampling depth The field sampling depth is 0-20 cm, and the orchard sampling depth is generally 0-20 cm and 20-40 cm. The sampling depth used for the determination of soil inorganic nitrogen content should be determined according to the depth of distribution of major root systems in different crops and different growth stages.
2, the number of sampling points To ensure enough sampling points, so that it can represent the soil characteristics of the sampling unit. Samples must be mixed at multiple points, taking 15 to 20 samples per sample.

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