Influence of organic sources on soil properties, yield and fruit quality of Guava (Psidium guajava L.) under organic farming

Organic farming is a holistic production management system that prioritizes environmental sustainability, encourages the natural recycling of organic matter and help sustain the ecosystem. The field experiment was carried out using a randomized block design with three replications and eighteen treatments, consisting of farmyard manure (FYM), neem cake (NC), vermicompost (VC), poultry manure (PM) and green leaf manuring (GLM) alone and with different combinations. The results revealed that significant improvement in physical properties of soil viz., maximum water holding capacity (68.2%) and mean weight diameter (1.31 mm) were observed when FYM + NC + VC + PM @ 2.5 kg plant^-1 each along with GLM @ 5 kg plant^-1 applied. Significantly higher organic carbon (0.46%), available nitrogen (N) (270.0 kg ha^-1), available phosphorus (P) (30.0 kg ha^-1), available potassium (K) (517.1 kg ha^-1) and DTPA-iron (Fe) (19.8 mg kg^-1), copper (Cu) (3.78 mg kg^-1), manganese (Mn) (10.52 mg kg^-1) and zinc (Zn) (1.60 mg kg^-1) were observed in the treatment with FYM + NC + VC + PM @ 2.5 kg plant^-1 each along with GLM @ 5 kg plant^-1 as compared to the other treatments. The enzymatic activity viz., urease, dehydrogenase and microbial populations viz., bacterial, fungal and actinomycetes were found significantly the highest in treatment combinations having five organic sources. The application of FYM + NC + VC + PM @ 2.5 kg plant^-1 each along with GLM @ 5 kg plant^-1 recorded significantly higher number of fruits plant^-1 (107.0), average fruit weight (189.9 g) and fruit yield (20.3 kg plant^-1 and 8.13 t ha^-1). Additionally, it resulted in higher total soluble solids (15.07° Brix), reducing sugar (6.05%), non-reducing sugar (3.30%), total sugar (9.35%), pectin content (1.15%), ascorbic acid (284.6 mg 100g^-1) and TSS/Acidity ratio (48.6) as compared to rest of the treatments.