Effect of integrated nutrient management in chickpea
Growth parameters
It is evident from the results presented that different INM treatments influenced crop growth from 30 DAS onward upto harvest of chickpea. The periodical plant height, number of branches per plant, dry matter accumulation per plant and volume of nodules per plant was significantly influenced by the integration of inorganic fertilizers with organic sources. Application of 100% RDF+
Rhizobium+PSB (T
3) recorded significantly higher plant height (Table 1) at 30, 60 DAS and at harvest but it was at par with 100% RDF (T
1) and 75% RDF+
Rhizobium+PSB (T
4) during first and second years and in pooled analysis. The increase in plant height with increase in different fertilizer levels and biofertilizer might be attributed to greater availability of nutrients with increase in application rate, which might have increased all the vital physiological processes, which in turn facilitated translocation of photosynthates to the growing meristematic tissues. It is well documented fact that application of phosphorus assists in absorption of metabolites, water and its further transformation for the growth of plant in terms of plant height. The plant height in chickpea tended to increase due to quick release of available nitrogen synthesized by root rhizobia to the plant at the time of vegetative growth. Similar results were reported by
Patel et al., (2007); Goyal et al., (2010); Singh et al., (2012) and
Singh et al., (2017).
Significantly higher number of branches per plant (Table 1) was observed in treatment 100% RDF+
Rhizobium+PSB (T
3) at 30 DAS during both the years as well as in pooled and remained at par with treatment 100% RDF (T
1) during first year and in pooled analysis, whereas in second year it was found at par with treatments 100% RDF (T
1) and 75% RDF+
Rhizobium+PSB (T
4). Application of 100% RDF+
Rhizobium + PSB (T
3) resulted in significantly maximum mean number of branches per plant at 60 DAS and at harvest during both the years and in pooled being at par with treatment 100% RDF (T
1) and 75% RDF+
Rhizobium+PSB (T
4). The increase in number of branches per plant to increasing fertilizer level and biofertilizers might be due to improvement in nutrient availability that enhanced horizontal expansion of chickpea by encouraging cell division in the meristematic region. These findings corroborate with earlier findings of
Patel et al., (2007); Singh et al., (2012); Tripathi et al., (2013) and
Singh et al., (2017).
Application of 100% RDF+
Rhizobium+PSB (T
3) reported significantly higher dry matter accumulation per plant (Table 1) at all crop growth stages during both years and pooled analysis and remained at par with treatment 100% RDF (T
1) and 75% RDF+
Rhizobium+PSB (T
4) at 60 DAS and at harvest except at 30 DAS being at par with 100% RDF (T
1) only during first and second years and in pooled results. This might be attributed due to better growth of plant in terms of plant height and number of branches per plant recorded with this treatment. Moreover, nitrogen and phosphorus might have increased the photosynthetic efficiency and thus increased the production of photosynthates. This is in agreement with the findings reported earlier by
Patel et al., (2007) and
Singh et al., (2017).
Significantly higher volume of nodules per plant (Table 1) at 30 DAS was recorded with treatment 100% RDF+
Rhizobium +PSB (T
3) and remained at par with 100% RDF (T
1) during first year. While, application of 100% RDF+
Rhizobium+ PSB (T
3) resulted in significantly highest volume of nodules per plant during second year and in pooled analysis. At 50 DAS, application of 100% RDF+
Rhizobium+PSB (T
3) produced significantly highest volume of nodules per plant during both the years as well as in pooled result. It was properly due to positive effect of biofertilizers and FYM by increasing the nodulation resulted higher fixation of atmospheric nitrogen and ultimately increased the growth characters.
Yield attributes and Yield
The treatment receiving 100% RDF+
Rhizobium+PSB (T
3) recorded significantly higher number of pods per plant, seed index, seed yield per plant, seed yield and stover yield (Table 2) but it was found at par with treatment 100% RDF (T
1) and 75% RDF+
Rhizobium+PSB (T
4) during both the years and in pooled analysis. This was largely attributes due to better growth of plant in terms of plant height, number of branches and dry matter accumulation per plant which resulted into adequate supply of photosynthates for development of sink. The complementary role was played by combining application inorganic fertilizer with biofertilizers in producing seed and stover yields of chickpea. These results are in close conformity with
Patel et al., (2007), Ali et al., (2010), Poonia and Pithia (2014),
Kumar et al., (2015) and
Singh et al., (2017).
Soil analysis
The soil available nitrogen and phosphorus (Table 3) recorded after harvest of chickpea was significantly higher due to application of 100% RDF+
Rhizobium+PSB (T
3) but it was found at par with 100% RDF (T
1) and 75% RDF+
Rhizobium+PSB (T
4) during both the years of study and in pooled result. This could be attributed to the fact that addition of inorganic fertilizers with biofertilizers and FYM to chickpea crop residues such as roots, stubbles, leaves, nodules and bodies of
Rhizobia rich in nitrogen and greater N fixation. Significantly higher available phosphorus might be due to the lower loss of nutrients due to slow available nutrients in soil. These results are in agreement with the findings of
Meena and Ram (2013) and
Dewangan et al., (2017). The available potassium content of soil after harvest of chickpea did not reach to the level of significance during both the years of study and in pooled analysis.
Economics
Maximum net monetary returns of and B:C ratio (Table 4) was recorded with application of 100% RDF+
Rhizobium+ PSB (T
3) followed by treatments 100% RDF (T
1) and 75% RDF+
Rhizobium+PSB (T
4). The increase in gross income, Net income and B:C ratio may be due to higher production because more availability of nutrient with combine application of nutrient sources. Similar results were also reported by
Kumar et al., (2015), Singh et al., (2017) and
Kumar et al., (2018).