More nutrients in the soil is not always better, as evidenced by salinity which causes plants difficult to take up enough water. Sodicity, or excess sodium in the soil, is distinct from salinity in its cause, its symptoms and its cure.
pH
Soil pH has not always been recognized as an important parameter for soil health and good crop production, but in fact has an overarching effect on nutrient availability, soil biology and indirectly the amount of nutrients that can be held in the soil as well as the soil’s structure.
Organic Matter
Organic matter is fundamental for the health of a soil’s biology, which affects the soil’s structure and nutrient availability. Organic matter helps soils receive and store more water, turning them essentially into free water storage tanks so that crops can survive temporary droughts.
Nutrient Availability and Soil Biology
The availability of nitrogen, sulfate and phosphate to crops is largely controlled by soil biology. Deficiencies of these nutrients may not be due to a lack of the nutrients themselves but a lack of one or more of the elements (organic matter, air, water, minerals and sufficient warmth) necessary to support soil biological health.
Improving Soil Fertility Sustainably
There are several approaches to improve the fertility of a soil:
SLAN – Sufficient Levels of Available Nutrients (“Feed the Plant”)
Build-Up and Maintenance (“Feed the Soil”), and
Base Cation Saturation Ratio (BCSR)
There are pros and cons to the first two and GYS can combine them to get the best of both worlds, based on the goals of the grower.
Estimated Nitrogen Release (ENR)
How best to determine if your soil will be able to meet the nitrogen needs of your crops throughout the entire growing season? Organic matter level and decomposition rate combined with soil texture and climate can be used to estimate available nitrogen during a season.
Electrical Conductivity
Concerned about your soil’s risk of salinity, particularly if you are using lower quality irrigation water? A pocket electrical conductivity (EC) meter is a low cost way to monitor your soil’s total salt level.
Calcareous Soils
Soils created from limestone, called calcareous soils, can be challenging to manage for good crop production since you may not be able to adjust their pH and associated nutrient availability issues. Understanding how to interpret soil test results for calcareous soils, and how best to fertilize them is critical for successful crop production.
Bulk Density
Unnecessary tillage is a waste of time, money and soil organic matter, but how do you know if the soil has enough air? Bulk density is a relatively simple test that can be done with simple equipment (no lab needed) to answer this question.
Base Saturation
Base saturation is the percentage of cation exchange sites in a soil occupied by either potassium, calcium, magnesium, sodium or hydrogen. Based on some claims, having these percentage within tight ranges is critical for growing healthy, abundant crops but decades of scientific investigation says otherwise.
Test Your Soil to Understand and Improve It
Each soil is unique, just as each of us is unique. To improve a soil, we need to first understand it, then add fertilizers that address its weaknesses and maintain its strengths. There is no fertilizer good for all soils (other than compost the soil produced itself) just as there is no medicine good for all people.
Irrigation Water and its Effect on Soils
When a soil receives water, it not only receives H2O but also all of the nutrients dissolved in that water. Even rain water contains additional nutrients. Particularly in arid regions dependent on irrigation water for crop production, we need to know how to apply irrigation water to not adversely affect the soil over time.