Soil Test Crop Response Based Gradient Experiment on Chakravarthi Keerai (Chenopodium Album) to Nitrogen, Phosphorus, Potassium Fertilizers in Western Ghats of Tamil Nadu

Chenopodium album, commonly known as lamb's quarters or bathua, is a plant of recognized nutritional value. It serves as a rich source of essential nutrients, including proteins, dietary fiber, minerals, and vitamins, especially iron and calcium. A field study employing inductive techniques was conducted to evaluate the growth performance and nutrient assimilation of Chakravarthi Keerai (var. Ooty 1) in response to a soil fertility gradient. In 2023, this investigation was carried out at the Krishi Vigyan Kendra, located in Dodabetta, Ooty district, Tamil Nadu, India. The experimental field was segmented into three adjacent strips, namely strip I (N0P0K0), strip II (N1P1K1), and strip III (N2P2K2), each receiving incremental levels of nitrogen (N), phosphorus (P₂O₅), and potassium (K₂O) through the application of urea, single super phosphate (SSP), and muriate of potash (MOP), respectively. The N1 dosage was determined based on the standard recommendation for Chakravarthi Keerai, while P1 and K1 levels were derived from the soil's nutrient fixation capacity, estimated at 250 kg ha-1 for phosphorus and 100 kg ha-1 for potassium. Chakravarthi Keerai var. Ooty 1 was grown as the test crop across the fertility gradient, and total biomass was measured. Plant samples were collected at harvest to determine the concentration of macronutrients (N, P, and K). Further, the nutrient uptake for nitrogen, phosphorus, and potassium was calculated. The findings revealed that applying graded doses of essential fertilizers (NPK) had a significant effect on soil nutrient status and plant nutrient uptake, and the biomass yield of Chakravarthi Keerai.