Soil Testing
Guidelines for Testing your Farm Soil
Soil Sample Collection Guidelines
It’s important to have your soil analyzed regularly before making any crucial crop nutrient management decisions such as adding fertilizers, or soil amendments.
Soil testing helps you better understand what nutrients are in your soil, what is your soil pH, and therefore determine how much lime or sulfur, and fertilizer you need to apply for the various crops you would like to grow.
Why Test Soil?
Standard soil tests provide information about soil pH (acidity or alkalinity); soil nutrient status: macronutrients - nitrogen, phosphorus, potassium, calcium, and magnesium, and micronutrients - zinc, copper, iron, and manganese.
Soil tests also give you information about the soil organic matter content and cation exchange capacity (CEC). CEC is the soil property that influences soil structure stability, nutrient availability, soil pH and the soil’s reaction to applied fertilizers and other soil amendments.
Tips for Collecting On-farm Soil Samples
Divide your greenhouse or farm into individual fields, blocks, or sections for soil sampling.
Collect samples that are representative of the field, section or block being sampled.
Do not sample unusual areas or areas that are too small to be amended separately, either with fertilizer or lime.
Walk in zigzag pattern in the field and collect 10 random soil samples from the block that you wish to test.
Use proper sampling tools, such as a soil sampling tube, auger, shovel or trowel.
Before digging the soil to collect a sample, remove any organic matter such as plants, weeds, and leaves from the surface of the sampling site.
Mix together all of the 10 or so individual soil samples from a block to make one representative sample for the block.
Identify the samples for different block separately by using unique letters or numbers.
Air dry the soil samples on some paper and in the sun until they are completely dry, before placing them into soil sample bags.
Get your soil tested by a commercial accredited lab for accurate information.
Soil labs often have specific protocols they would like you to use for sampling soil and for storing the soil sample, before shipping to the lab. Contact the lab and ask them about their soil sampling requirements before sending off soil samples for testing.
Use a shovel or soil auger to collect soil samples from a representative section of the field.
Remove any roots or other plant materials from the soil and mix the soil thoroughly.
Label the soil samples and follow the packing instructions from the soil testing lab.