Effect of micronutrient loading, soil application, and foliar sprays of organic extracts on grain legumes and vegetable crops under marginal farmers' conditions in Nepal.

Various methods of micronutrient supplementation such as nutrient loading through priming water, soil application of micronutrient fertilisers, and foliar spray of cattle urine or stinging nettle (Urtica dioica L) extracts were evaluated on chickpeas, field peas, mung beans, cucumber, broad-leaf mustard, and radishes under farmers’ management conditions in the Terai and hills of Nepal. Soil analysis showed that the soils were low to medium in boron and zinc with moderately acidic reactions. In chickpeas, soil application of borax at 20 kg ha and zinc sulphate at 14 kg ha gave significantly higher yields over the control treatment. Similarly, loading 0.05% sodium molybdate through priming solution and soil application of molybdenum at 0.5 kg ha (sodium molybdate at 1.22 kg ha) resulted in an increase in nodulation and yield in both chickpeas and mungbeans. Four to five foliar sprays of cattle urine diluted to 20% with water increased field pea and chickpea yields by 27 and 11%, respectively. In a different set of on-farm trials, six to 10 foliar sprays with a 20% solution of stinging nettle extract at 15-day intervals increased seed yield of broadleaf mustard, radishes, and peas by 31, 18, and 14% respectively over the control treatments. In a similar study on cucumber, over 50% increase in fruit yield was observed after spraying of nettle extract. There is further scope for research for developing efficient methods of applying micronutrients and exploring the use of plant extracts for invigorating crop growth and increasing yield under marginal conditions.