Fertilizer requirement for Groundnut Cultivation

Groundnut is a legume and nitrogen-fixing crop, which means it can convert atmospheric nitrogen into usable forms for itself and helps improve soil fertility. However, it still requires other nutrients, such as phosphorus, potassium, and calcium, for optimal growth and yield. It is known to respond well to residual soil fertility. This means that groundnut plants can thrive in soils that have been previously fertilized, even if no fertilizer is applied directly to the groundnut crop itself.

Crops that precede groundnut in a cropping rotation should be well fertilized, particularly with phosphorus (P) and potassium (K). Phosphorus and potassium are essential nutrients for groundnut plants, and they are not fixed from the air like nitrogen. Therefore, it is essential to ensure these nutrients are present (or added) in the soil before planting groundnuts.

The basics of the fertilization strategy 

The recommended fertilizer application for groundnut cultivation varies depending on the soil type, soil test results, climate, and expected yield. For soil testing, samples from the fields to be sown with groundnut must be analyzed to determine the status of macronutrients and micronutrients; soil samples (6-8) should be collected from different places in the field at plow depth. Samples should be bulked and mixed thoroughly to draw a representative field sample for analysis at any authorized agricultural soil testing lab [1].

Farmers usually apply farm yard manure/ compost of around 10-12 tonnes /ha once in 2 – 3 seasons. NPK recommendations should be based on the results of the soil analysis.

Groundnut growers apply 20N + 40 P₂O₅ + 60 K₂O kg/ha as basal for the kharif (rainy season) crop. Phosphorus should be applied through single superphosphate. While for rabi (post-rainy season), farmers use 25N + 50 P₂O₅ + 75 K₂O kg/ha as basal and 10N kg/ha at flowering [2].

Generally, a basal application of 40-60 kg of phosphorus per hectare is recommended for groundnut plants. This can be applied as single superphosphate (SSP) or triple superphosphate (TSP). A top dressing of nitrogen fertilizer may also be applied at the early pod formation stage at a rate of 20 kg per hectare. The best source of nitrogen fertilizer for groundnut is ammonium sulfate, as it also contains sulfur, which is another important nutrient for this crop.

In addition to phosphorus and nitrogen, groundnut also requires potassium and calcium. Potassium helps improve the plant’s overall health and vigor, while calcium helps prevent Blossom End Rot and, more importantly, pod and seed development. The recommended application rate of calcium (in the form of gypsum) fertilizer for groundnut cultivation is 250 kg per hectare. Gypsum should be applied when flowering, and it should not come in contact with the foliage as it may cause scorching of leaves. Gypsum application should be followed by light inter-cultivation or hand weeding to ensure its incorporation into the soil.

Micronutrients are also important for groundnut growth and yield. The most important micronutrients for this crop are zinc, manganese, and copper.

Zinc deficiency can lead to stunted growth, while manganese deficiency can cause chlorosis (yellowing of the leaves). Wherever Zinc deficiency is observed, growers are advised to apply 25 kg/ha Zinc sulfate once in 3 seasons. In average soils, 2-3 kg per hectare for zinc is preferred.

Copper deficiency can lead to poor pod development and yield. The recommended application rates of micronutrient fertilizers for groundnut cultivation are 1-2 kg per hectare for manganese and 0.5-1 kg per hectare for copper.

It is important to note that these are general recommendations. The actual fertilizer requirements for groundnut crop may vary depending on the specific conditions in the location and country. It is always best to consult a local agricultural expert for the best recommendations for specific needs.

Here are some additional tips for fertilizing groundnuts:

• Apply fertilizers evenly over the soil surface.
• Do not apply fertilizers too close to the plants, as this can burn their roots.
• Water the soil well after applying fertilizers.
• Test the soil regularly to determine the nutrient levels and adjust your fertilizer application as needed.

References:

https://agritech.tnau.ac.in/agriculture/agri_nutientmgt_groundnut.html

1. N. Nigam, 2015. Groundnut at a glance.
2. L. Singh and Vidya Chaudhari, 2005. Macronutrient requirement of groundnut: effects on growth and yield components. Indian J. Plant Physiol, vol. 11, No.4 pp. 401- 409.

Further reading

Groundnut: Plant Information, History, Uses and Nutrition Value

Principles of selecting the best varieties of Groundnut: A Comprehensive Guide

Groundnut Soil requirement, Soil preparation and Planting

Weed Management in Groundnut Farming

Fertilizer requirement for Groundnut Cultivation

Irrigation Requirement and Methods for Groundnut Cultivation

Groundnut Diseases and Management Practices

Groundnut Insects, Pests, and their Management

Harvesting, Drying, Curing, and Storage of Groundnut