Impact of fodder grasses and organic amendments on productivity and soil and crop quality in a subtropical region of eastern Himalayas, India

• Four fodder crops under 3-sources of nutrients compared in a 3-year study.
• Hybrid napier recorded the highest (28.1 Mg ha−1) average dry fodder yield.
• Mean dry fodder yields under organic was 27.5% higher than inorganic fertilizer
• Perennial forages improved soil quality and SOC stocks.
• Organic sources of fertilizers improved SOC stock by ∼10% after 3-years.

Agriculture in the Eastern Indian Himalayas is characterized by fragility and marginality with about 77% of the geographical area under hills and degraded plateau. Thus, field experiments were conducted for three consecutive years during 2008–2011 to assess the impact of perennial fodder grasses and sources of nutrient supply on productivity and quality of soil and fodder under terrace conditions in a subtropical degraded hill soil of Meghalaya, India (980 m above sea level). The treatment consisted of four fodder crops and three sources of nutrients. Fodder crops were broom grass (Thysanolaena maxima), congosignal grass (Brachieria rosenesis), hybrid napier (Pennisetum typhoides x P. purpureum) and guinea grass (Panicum maximum). Three sources of nutrient supply were organic, inorganic and control (inherent soil fertility conditions). Farmyard manure (FYM) was used as organic source of nutrient supply on N equivalent basis and P nutrition was supplemented through rock-phosphate. Fertilizer urea, single super phosphate and muriate of potash were used as inorganic source of nutrients. The dry fodder yield increased in each successive year and three year average dry fodder yield was significantly higher with hybrid napier (28.1 Mg ha−1) than other grasses. Among nutrient sources, the average dry fodder yield under organic amendment (22.9 Mg ha−1) was 27.5 and 64.4% higher than that under inorganic fertilizer (17.9 Mg ha−1) and control (13.9 Mg ha−1), respectively. Crude fibre (35.9%) and lignin (7.02%) concentrations were the maximum in hybrid napier whereas, cellulose (39.1%) was the highest in congosignal grass. On the contrary, crude protein concentration was the maximum in broom grass (8.27%), and it was at par with that in hybrid napier. The available N, P, K and soil organic carbon (SOC) contents were significantly higher (P = 0.05) under organic compared to those under other nutrient sources. The SOC concentration (17.2 g kg−1) and stock (32.2 Mg ha−1) after three years under organic treatment was 5.3 and 2.1% and 13.3 and 8.1% higher than that recorded under inorganic and control, respectively. The study indicated suitability of fodder grasses and organic amendments in improving quality of marginal degraded hill soils.