Integrated Use of Organic and Inorganic Fertilizers with Bio-inoculants on Yield, Soil Fertility and Quality of Apple (Malus domestica)

A study was conducted during 2007 and 2008 on integrated use of organic and inorganic fertilizers with bio-inoculants on yield, quality of apple (cv. Red Delicious) and soil fertility. Highest fruit yield (166 kg tree⁻¹) was recorded in recommended dose of fertilizer (100% NPK) treatment (T₂) followed by 100% NK+50% P + arbuscular mycorrhizal fungi (T₄) and increased fruit yield to the tune of 34 and 29% over control, respectively. Similarly, N and K content in leaves and N, P and K content in fruits were recorded maximum in recommended dose of fertilizers (RDF) (T2) but highest P content in leaves was observed in treatment comprising of vermicompost @ 10 kg tree⁻¹ + Azobacter + Azospirillum + arbuscular mycorrhizal fungi (T₁₃). Fruit quality attributes, in terms of total soluble salt (TSS), total sugars and ascorbic acid were recorded maximum with T₁₃ treatment which was significantly higher than T2 whereas, maximum acidity was found in control (T1) treatment. Maximum soil organic carbon (13.0 g kg⁻¹) was recorded under T₉ followed by T₇ (12.7 g kg⁻¹) which was significantly higher over application of inorganic fertilizers with and without integration of biofertilizers. Treatment T2 also recorded highest available soil N and K, whereas highest available soil P was observed under T₁₃. The build-up of available soil P due to T₁₃ and T₉ treatments was 13 and 11% over initial status of P, respectively. Conjunctive use of biofertilizers with vermicompost proved to be superior to FYM in terms of yield and yield attributes of fruit, nutrient content in leaves and fruits, quality of fruit and soil fertility. However, soil organic carbon was found to be maximum in the FYM-treated plots.