Nitrogen Requirement:
Mungbeans generally require up to 60 to 70 kg/ha of nitrogen per tonne of grain yield in favourable seasons. The crop will use nitrogen from the soil, nitrogen supplied by fertilisers and nitrogen fixed by the crop. The more nitrogen the crop can access, the more it will use. So a 1.5 tonne/ha crop has a total nitrogen requirement of 100 kg N/h, but the crop generally shouldn’t need nitrogen fertiliser, provided plants have effectively nodulated. Low rates of nitrogen fertiliser may be justified in situations such as:
• double-cropping immediately after winter cereals, where low rates of nitrogen (and sulphur) can get the plants off to a good, quick start. Maybe just consider 20–30 kg/ha SOA or a Starter 15, depending on soil P levels
• in late planted crops where plants often fail to make sufficient growth to support a reasonable grain yield, consider using Starter Fertiliser + Zinc.
Phosphate Requirement:
Large plant responses to applied phosphate fertilisers are likely in situations where soil bicarbonate P levels are below 25 mg/kg.
Sulphur Requirement:
Sulfur deficiency is most likely to occur in double-crop situations where sulfur levels in the soil have been depleted by the previous crop. Apply SOA at 20–30kg/ha will rectify a sulfur deficiency.
Zinc Requirement:
Mungbeans are very responsive to zinc. Crop responses are likely where soil test levels are:
• below 0.8 mg/kg on alkaline black earths, grey clays and alluvial soils
• below 0.4 mg/kg on acid soils.
