Before deciding on what fertiliser is required for your crop, you need to establish how fertile (or otherwise!) the soil is.
A soil test should be carried out every 3 – 5 years to determine the soil pH and the levels of major and trace elements. This test will provide the basis for a cost effective fertiliser programme for your crop.
It is important to apply lime well before sowing as it takes some months to affect the soil pH. How often lime is needed depends on rainfall, soil type and its pH value, land use and on what other fertilisers are being used.
For high yields, the soil pH should be 6.5 - 7.0. If the soil analysis shows that a lime application is recommended, you get an immediate benefit if it can be applied to the ploughed ground prior to sowing, whether in spring or the previous autumn.
Beans have no requirement for applications of nitrogen fertilisers. This crop is a legume, which means that it benefits from a symbiotic relationship with Rhizobium bacteria. These bacteria are present in the root nodules of leguminous crops and can supply the plant with nitrogen fixed from the air
Phosphorous and Potassium
P and K requirements (kg/ha) for beans
Apply fertiliser (0-7-30 / 0-10-20) pre-ploughing or pre-cultivation as per soil analysis.
• Ideally P and K fertilisers should be worked into the seedbed during cultivation before drilling.
|Field Peas and Beans Nitrogen, Phosphorus and Potassium|
*The fertiliser should be broadcast after ploughing and cultivated deeply into the seedbed.
Apart from the major nutrients i.e., N, P, and K, other minerals are also important. These are only usually required in very small amounts and hence they are referred to as trace elements or minor nutrients.
Despite being required in very small quantities, a deficiency (or excess) can occur in certain situations, and can result in poor crop performance and reduced yields. As a general rule, if the soil levels of trace elements are adequate for a cereal crop, then they will be adequate for an alternative combinable crop.
The most common trace element deficiencies are of manganese (Mn), magnesium (Mg) boron (B) and sulphur (S).
Nitrogen is not required for field peas or beans, Because of the risk to germination, K should not be combined drilled.