Soil Fertility and Plant Nutrition Research Under Controlled Conditions: Basic Principles and Methodology

ABSTRACT

In modern agriculture, use of essential plant nutrients in adequate amounts and proper balance is one of the key components in increasing crop yields. Further, in developing crop production technologies, research work under field and controlled conditions is necessary to generate basic and applied information. In addition, research is very dynamic and complex due to variation in climatic, soil, and plant factors and their interactions. This demands that basic research information can only be obtained under controlled conditions to avoid or reduce effects of environmental factors on treatments. Hence, the objective of this article is to discuss basic principles and methodologies of research in soil fertility and mineral nutrition under controlled conditions. Topics discussed are soil and solution culture experimental techniques including, fertilizer application and planting, liming acid soils, experimental duration and observations, composition of nutrient solutions, preparation and sources of iron (Fe) in nutrient solutions, pH of nutrient solutions, and stable supply of nutrients in the solution culture.

Keywords:

• field crops
• mineral stress
• root growth
• soil and solution culture

Notes

^a F0 = zero fertility level; F1 35 kg N ha⁻¹, 50 kg P₂O₅ ha⁻¹, 40 kg K₂O ha⁻¹, 5 kg Zn ha⁻¹ and 2 Mg ha⁻¹ dolomitic lime for upland rice and 60 kg N ha⁻¹, 80 kg P₂O₅ ha⁻¹, 60 kg K₂O ha⁻¹, 5 kg Zn ha⁻¹ and 2 Mg ha⁻¹ dolomitic lime for irrigated rice. These levels correspond to recommended under field conditions in Brazil during 1980 to 1990 for upland and lowland rice. The F4 and F8 are 4 and 8 times nutrients levels those recommended under field conditions. D1, D2, D3 and D4 correspond to 1, 2, 3 and 4 plants per pot.