Home News Sulphur (s) as the fourth macronutrient in corp nutrition

Sulphur (s) as the fourth macronutrient in corp nutrition

To minimize the gap between the demand and supply of cereals, oilseeds and pulses, intensive efforts are being made to increase their production.

As ever-increasing population and urbanization cannot allow increase in the land area under the cultivation of cereals, oilseeds and pulses anymore, yield per unit area needs to be improved further.

To achieve this objective, agricultural scientists have laid more emphasis on improving production of these crops through proper nutrition of the crops by evolving high yielding varieties and adopting improved agronomic practices as well as plant protection measures etc.

The most important constraints to crop growth are those caused by the shortage of plant nutrients.

Sulphur is increasingly being recognized as the Fourth major plant nutrient after Nitrogen (N), Phosphorus (P) and Potassium (K). The importance of S in agriculture is being increasingly emphasized and its role in crop production is well recognized.

“Based on years of cumulative experience with sulphur testing, almost every soil tested does not have enough sulphur to produce top yields unless it is specifically added as part of the fertility program.” – Neal Kinsey and Charles Walters, Hands-On Agronomy, Acres U.S.A., August 1999

This is the not different for the Kenyan soils!!

Why there  is  Shortages of Sulphur in Kenyan Soils.

  • Changing agricultural practices have led to Low Organic Matter in the soils reducing the amount of Sulphur in the soil.
  • Sulphur Dioxide(SO₂) in the atmosphere is now less due to mandated emissions control
  • Sulphur Containing fertilizers are being used less and less e.g. ASN, AS, and K₂SO4.

These Sulphates leach easily with high rainfall, or under irrigation.

  • With the application of Sulphates only, as source of sulphur mostly in low organic soils there is no build up of Sulphur in the soil.


Facts about Sulphur:

  • Sulphur is a macro element in plant nutrition.
  • Elemental Sulphur IS available to plants.
  • Oxides are converted to sulphates along with Sulphur.
  • Sulphur and Phosphorus levels required run more or less parallel i.e. Sulphate is needed for growing plants just as badly and in much the same amounts as phosphates.
  • Nitrogen: Sulphur ratio is critical for optimal Nitrogen availability.

Why is this Nutrient Extremely Important and much needed by crops?

  • Helps seedlings survive in cool, moist soils especially in early planted fields or for conservation tillage fields.
  • Provides 50% more root development during early periods of growth.
  • Sulphur is needed to make and increase protein content of the crops and increases oil content of crops like (Rape Seed) Canola.
  • Sulphur is needed in plants to craft chlorophyll and to fabricate enzymes and vitamins.
  • It promotes nodule formulation in legumes.


Elemental Sulphur is the Solution!!

Sulphur is needed through all stages in plants growth.

Soils needs to have at least 10% Sulphur in sulphate form available early in the crop season for germination and seedling growth then the rest 90% along the season.

To achieve this, 10% can be supplied with commercial fertilizers like AS, ASN or MgSO₄ since they contain sulphur in sulphate form which is readily uptaken by plants.

For the 90% Sulphur needed along the season relying on slow release source like elemental sulphur is the best. This Sulphur is not subject to leaching and is slowly released as it oxidizes in the soil.

Therefore , farmers need to plan their fertilizer program to contain this crucial nutrient. To achieve a sustainable supply of sulphur throughout the crop season elemental Sulphur can be blended with Planting fertilizers like DAP or MAP.

With Amiran TIGER TRACE product i.e. granular pure Sulphur based product with trace elements in oxide form, the farmer can achieve a continuous Sulphur supply throughout the crop season. The Sulphur oxidizes slowly releasing sulphur in sulphate form and trace elements in a form readily available for plant uptake.

This fertilizer product is granular (size 2-4mm) and can be blended with all field grade fertilizers applied especially at planting.