Gypsum is calcium sulfate fact that can be found in three forms: the hemi hydrate (gypsum CaSO42H20 =), di hydrate (CaSO41/22H20) and anhydrite (CaSO4). This is one of the few products to meet the three categories used in the most important agriculture is: amendment, conditioner and fertilizer. The use of gypsum enables the bacteria in the soil, improve nutrient uptake, enhance resistance of plants, and greatly facilitates the development of roots. Due to its high calcium content, gypsum promotes excellent soil structure, especially by promoting the abundance of earthworms.
All cultures benefit from the application of gypsum. Some plants will benefit more than others, such as potatoes, tomatoes, onions, blueberries, canola, cabbage, corn or alfalfa. These are plants with particularly high needs calcium, sulfur or acid-loving plants whose calcium intake can not be achieved by the application of lime (blueberries). As a source of calcium, gypsum advantages are that it is a hundred times more soluble than lime and it does not change the soil pH.
Following the application of gypsum before or immediately after planting (1-2 tonnes / hectare with subsequent shallow incorporation) or in the fall (2-4 tonnes / hectare with subsequent deep incorporation), there has been an increase in tuber yield and reducing the incidence of internal brown spotting, scab, and hollowheart.
Calcium deficiency for tomatoes results in a brown spot appearing at the tip of fruit (blossom-end rot). By expanding, this stain dries and blackens. This damage can cause rot and complete loss of fruit. The application of gypsum can prevent symptoms and losses from this type of rot.
In cruciferous crops (cabbages, turnips, radish, canola), calcium deficiency may cause severe physiological disorders of development (eg, tip burn, hollow stem).
An Agriculture Canada study published in 1996 to compare the applications of potassium sulphate and gypsum (calcium sulfate) ability to meet the sulfur’s nutritional needs in cabbage grown in Prince Edward Island. Use of gypsum has achieved a level of sulfur in the cabbage leaves two times higher than the potassium sulphate. In addition, the weight yield was highest in plots treated with gypsum, and in the 5 different sites used for this research.
In Quebec, it is well known that adding 15 to 20 kg / ha of sulfur can be profitable in canola crops because its high sulfur uptake. According to Environment Canada, the atmospheric input of sulfur from precipitation have decreased significantly since the mid-1990’s.
(Ref: CRAAQ, fertilization Reference Guide, 2nd edition, 2010.)
Symptoms of calcium deficiency in blueberries areyonug leaves tips necrosis . In cases of severe deficiency, we observe the death of the terminal bud on the stems and roots. The leaf margin stops growing while the leaf continues to grow. The leaf takes a convex or concave shape and is deformed with tears, especially at the tip of the leaf.
A study in Prince Edward Island by Agriculture Canada between 1998 and 2001 (two production cycles) confirmed that the use of gypsum significantly increased the uptake of minerals (P, Ca, K, Mn, S) blueberry plants. In their study, they confirm that no other treatment has increased as the overall health of plants. The use of gypsum is a good alternative in the commercial production in that the mineral uptake increase has a positive overall effect on the whole plant.
Litter for animals:
One of the many benefits of using gypsum as litter for animals is the reduction of odors. The sulfate from gypsum (SO4 -) is reacted with ammonia or ammonium (NH4 +) to form ammonium sulfate. The smell is thus neutralized by an ammonium salt soluble easilym assimilated by plants suites spreading.
Cases of mastitis in dairy cows can be reduced with the use of gypsum litter.
Ammonia and ammonium are forms of nitrogen. By fixing these nitrogen sources with sulfate, odors are reduced but also decreases the volatilization of nitrogen. During the spreading of manure, nitrogen remains less prone to runoff or leaching. It is a major economic benefit motivating the use of gypsum as litter.