Agronomy is defined as managing or improving soil and water use to cultivate the best crop yields to address food security. Agronomy is divided into three spheres: crop science, soil science and environmental science. Various fundamental principles are described that must be considered within an agronomic system.
The fundamental principles of agronomy are:
- Planning, programming and implementing.
- Choice of crop varieties and planting times.
- Proper field management.
- Adaptation of different cropping systems.
- Timing of fertiliser application.
- Choice of seed quality, planting space and soil depth.
- Water management and drainage capability.
- Crop protection measures.
- Suitable management practices.
- Suitable and timely harvesting methods.
- Suitable harvest storage.
Each principle plays an important role in a successful agronomic system.
- Planning, programming and implementation are fundamental in any agronomic system as they can have a direct influence on its sustainability. It involves the capital and labour required, the steps that will be taken to ensure the cropping system chosen is suited for the soil, climatic conditions and water availability of the area as well as access to market facilities.
- The choice of crop varieties and their planting times will be influenced based on the land situation, agro-climate, soil depth and fertility, planting season and method of cultivation as well as an available market for the chosen crops.
- The most appropriate field management techniques are also fundamental as it includes the tillage methods and depth to be applied, preparation of field channels to accommodate irrigation and drainage as well as the management of topsoil erosion.
- Different cropping systems may be required for specific crops to ensure high yields and harvesting even under adverse environmental conditions.
- The timing of fertiliser applications and irrigation schedules is important to ensure sufficient and balanced crop nutrient and moisture supply. This can be established through soil analysis, to determine the nutrient status and moisture retention capability of the soil, before application, thereby limiting unnecessary costs and salt build-up.
- Choosing the best quality seeds and planting at the desired intervals and depth can ensure seed germination with increased yields. It can also ensure healthy and uniform seedlings.
- Proper water management is fundamental, especially the quality of water used as poor-quality water can increase salt concentration in soil which influences soil hydraulic conductivity and crop water uptake. Strict water management should therefore be implemented to improve soil moisture and not leach nutrients from the soil.
- Crops should be protected against pests, pathogens and weeds with needed control measures that will not influence crop production or deteriorate crop quality. Crops can also be protected with border trees or other defence mechanisms against harmful climatic conditions such as strong winds.
Adopting suitable management practices that benefit crop production and increase yields is also fundamental and thus requires constant monitoring and problem-solving.
- The timing of harvesting is important to ensure crops have reached physiological maturity before harvest, while the most appropriate harvesting techniques are also fundamental to reduce field damage and ensure crop quality. Harvesting techniques are also fundamental in managing crop residue to sustain soil fertility and decrease topsoil erosion.
- The correct storage methods and facilities are important to maintain crop quality and ensure its shelf-life.