Calcium deficiency can often be assessed through what soil test?

Calcium deficiency in soil can effectively be evaluated using a saturated paste extraction test. This test involves saturating a soil sample with water and allowing it to drain, which helps create a solution that reflects the availability of nutrients, including calcium, in the soil moisture. By analyzing this extract, agronomists can determine the concentration of calcium and assess whether it is at sufficient levels for optimal plant growth. This method provides a direct measurement of the nutrients accessible to plants and can help identify deficiencies that might affect crop yields.

Other options, such as basic cation exchange capacity, while related to soil fertility, do not specifically measure the current nutrient availability directly like the saturated paste extraction. Basic cation exchange capacity indicates the soil's ability to hold cations but does not quantify the current levels of calcium. Soil moisture tests focus primarily on the water content of the soil and not on nutrient levels. Organic matter analysis gives insight into soil health and nutrient retention capacity but does not directly reveal calcium availability. Thus, the saturated paste extraction stands out as the most reliable method for assessing calcium deficiency.