Q39: Which is the most widely used method to determine the... - Soil Fertility, Plant Nutrients & Fertilizer Technology - RPSC Agriculture Research Officer (Agriculture Chemistry) Screening Test - 2024 | Agrigyan

The hot water extraction method developed by Berger and Truog (1939) is the most widely used standard test for available boron in soils.

• Johnson and Nishita (1952): Classic reduction distillation method used for the determination of total and available sulfur in soils and plants.
• Williams and Steinberg (1959): Method designed for available sulfur fractionation in soil.
• Berger and Truog (1939): Developed the hot water-soluble boron extraction method, where boron is extracted by boiling with water and determined colorimetrically using azomethine-H or curcumin.
• Lindsay and Norvell (1978): Developed the DTPA micronutrient soil test for zinc, iron, copper, and manganese in neutral and calcareous soils.