Impact of Organic Rice Farming Practices on Soil Nutrient Status in Farmers’ Fields of Nandyal District of Andhra Pradesh, India
S. Balaji Nayak *
Regional Agricultural Research Station, Acharya N.G Ranga Agricultural University, (ANGRAU), Nandyal - 518 502, India.
M. Jyosna Kiranmai
Regional Agricultural Research Station, Acharya N.G Ranga Agricultural University, (ANGRAU), Nandyal - 518 502, India.
Y. Satish Kumar
Regional Agricultural Research Station, Acharya N.G Ranga Agricultural University, (ANGRAU), Nandyal - 518 502, India.
G. Fareeda
Regional Agricultural Research Station, Acharya N.G Ranga Agricultural University, (ANGRAU), Nandyal - 518 502, India.
P. Kavitha
Regional Agricultural Research Station, Acharya N.G Ranga Agricultural University, (ANGRAU), Nandyal - 518 502, India.
*Author to whom correspondence should be addressed.
Abstract
A field investigation was conducted to assess how the duration of organic rice farming was associated with selected soil physicochemical properties in farmers’ fields of Nandyal district, Andhra Pradesh. Sixty surface soil samples (0–15 cm) were collected from fields managed organically for less than 2 years, 2–5 years, or more than 5 years, with 20 samples in each category. Soil pH, electrical conductivity (EC), organic carbon (OC), and available nitrogen (N), phosphorus (P₂O₅), and potassium (K₂O) were determined using standard laboratory procedures. Mean soil pH varied only slightly, from 7.33 to 7.38, indicating neutral to slightly alkaline conditions across the duration groups. Mean EC declined from 0.35 to 0.25 dS m⁻¹, whereas mean OC increased gradually from 0.32% to 0.34%. Available N increased from 245 kg ha⁻¹ in the initial category to 266 kg ha⁻¹ after 2–5 years and remained comparatively high at 260 kg ha⁻¹ after more than 5 years. Mean available P₂O₅ was 61.4, 45.3, and 46.2 kg ha⁻¹ across the respective groups, while available K₂O remained high at 307, 304, and 311 kg ha⁻¹. These descriptive findings indicate that longer organic management was associated with lower EC, slightly greater OC, and comparatively high N and K availability, while the phosphorus pattern was not consistently increasing.
Keywords: Organic farming, soil fertility, organic carbon, available nutrients, soil health