Effect of Integrated Nutrient Management on Yield Attributes and Yield of Black Gram Cv. Pu-31

The field trial was conducted during the kharif-2019 on the research farm of TCA Dholi at the Dr. Rajendra Prasad Central Agricultural University, Pusa campus in Samastipur (Bihar). The experiment has eighteen treatment combinations, comprising three nutrient management practices i.e., fertilizer (75%, 100% and 125% RDF), organic manure (control and FYM@ 5 t ha^-1) and biofertilizer (rhizobium, nutrient mobilizer and rhizobium + nutrient mobilizer). The experiment was laid out in factorial randomized block design with three replications. The variety of Black gram “pant urd-31” was sown in last week of July with a spacing of 30 cm × 10 cm and seed rate of 20 kg ha^-1. The soil of the experimental plot was calcareous in nature having pH of 8.15 and EC at 0.37 dSm^-1. The soil was moderately fertile being medium in Organic carbon (0.43), available nitrogen (175.6 kg ha^-1), phosphorus (18.4 kg ha^-1) and potassium (124.17 kg ha^-1). The recommended doses of fertilizer (RDF) of black gram was 20:45:20 kg NPK ha^-1 respectively. The amount of manure and fertilizer are calculated according to the treatment details and applied sowing time. Fertilizer was applied in lines 7-10 cm away from the main lines of the seed in the form of urea (46%), SSP (16% P₂O₅) and muriate of potash (60% K₂O) and organic manure through farm yard manure were applied at sowing time as per treatment details and Biofertilizer (viz., Rhizobium, Nutrient Mobilizer and Rhizobium + Nutrient Mobilizer) was applied as seed treatment. The monsoon usually begins in the third or fourth week of June and last until September. During the period, a total of 719.4 mm of rainfall was received. The average maximum and minimum temperatures were 31.50°C and 25.27°C. The average maximum and minimum relative humidity was recorded 97.38% and 82.24%, respectively. For observation of crop, five selected plants were tagged for further identification and were monitored for growth and yield parameters. The results were analyzed as per statistically standardized principle of ANOVA technique described by Gomez and Gomez (1984) at 5% level of significance.

The results show that balancing use of nutrition in black gram with various sources (i.e. fertilizer, manure and Biofertilizer) effectively improves the yield (Fig 1 and Table 3) of black gram with various yield attributes (Table 2) and growth parameters (Table 1).
 

 

 

 

 
Effect of fertilizer
 
The significant difference was not observed at 20 DAS in the growth of crop of the black gram. With application of fertilizer, significantly higher plant height (48.54 cm), number of branches plant^-1(4.49), dry weight plant^-1 (9.71 g), crop growth rate (13.57 g day^-1 m²) were observed in F₃-125% RDF at 60 DAS respectively. But statistically at par plant height (46.42 cm), number of branches plant^-1(3.75), dry weight plant^-1 (8.81 g), crop growth rate (12.65 g day¹ m²) were found in F₂-100% RDF. The higher growth indices were due to the better nutrients availability at the critical stage which facilitates better nutrient transfer and accumulation of dry matter. These findings are in line with Mere et al., (2013). Application of fertilizer F₃-125% RDF gave significantly higher yield attributes such as pod plant^-1 (34.99), grain pod^-1 (5.53), length of pod (4.39 cm), test weight (40.22g) over 100% RDF while at par pod plant^-1 (33.35), grain pod^-1 (5.35) and length of pod (4.11 cm). Higher yield parameters may be due to higher levels of inorganic fertilizers increasing efficiency of photosynthesis and activity of enzymes responsible for energy transformation. Kumar et al., (2014) also found similar results in there experimentation. Grain yield is main and more important than total biological retention which has resulted in different combination of many physiological processes depending on the environment in which it was grown. Final value of yield of many plant species comes from the source-sink ratio and the various components of the sink such as the pods plant^-1, seeds pod^-1 and test weight. Source component can be the assimilation reserve of leaves before flowering. The accumulate and translocate of photosynthates’ depends on the efficient photosynthetic structure and source-sinking condition growth and development in early stages of crop production as the final yield depends on all components of the source and sink operating in different phenophase of growth during the plant life cycle. The increasing availability of important nutrients to plants leads to increased early root growth and cell proliferation, leading to greater absorption of other nutrients from deeper layers of soil and ultimately increased growth parameters, straw yield, grain yield biological yield and harvest index. (Dhaka et al., 2016). In the present study black gram grain and straw yield significantly influenced with treatments due to different inorganic fertilizer. Grain and straw yield (10.78 and 22.61 q ha^-1 respectively) were significantly higher using 125% RDF and was on par with grain yield (10.73 q ha^-1) and straw yield (22.20 q ha^-1) with 100% RDF. This may be due to the higher yield attributes occurred and supported to produce higher yield under this treatment. Similar result found Mere et al., (2013) in soyabean and Kumar et al., (2014) in rice.
 
Effect of organic manure
 
Integrated nutrient management ensures high productivity of crop, minimize fertilizer costs, improves the physical properties of soil with efficiency of added nutrients as well as ensuring good soil health and an environmental friendly approach. Although Organic manures play a crucial role in the long term depletion of nutrients through the plants while inorganic pose a greater threat to sustainability therefore turn to enhanced use of organic manure which is necessary to sustain the yields or quality of produce of crop. The use of the organic manure alone does not result in spectacular increase in yield. Therefore, the aforementioned conclusion facilitated the cultivation of black gram using organic and inorganic fertilizers with integration. The current general recommendation on fertilizers does not ensure the efficient and economical use of nutrients (Singh, 2018). The significant effect was not observed at 20 DAS in the growth of crop of the black gram with application of manure but at 60 DAS significantly maximum plant height (47.51 cm), number of branches (4.11), dry matter (9.39 g plant^-1) and CGR (13.21 g day^-1m²) in M₂- FYM @ 5 tons ha^-1 treatment were registered as compared to M₁- control (no application of FYM). Increase growth at different phase of crop may be supply of nutrients from FYM and that manure provides nutrition to plants for longer duration compared to without FYM application. The combined and balanced nutrition of primary, secondary and trace elements from source of organic manure with improvement of the physiological efficiency therefore efficient absorption, translocation and assimilate of nutrients results increasing plant dry matter accumulation and nutrient content. The positive effects of FYM on growth may be the supplementary supply of plant nutrients and enhanced fertility status of the soil (Datt et al., 2003). The organic manure significantly increased the number of pod plant^-1 (33.99), grain pod^-1 (5.50), length of pod (4.39) and test weight (40.19 g) with M₂- FYM @ 5 tons ha^-1 treatment over M₁- control. Higher yield attributes can be proposed when application of manure because the beneficial effect of manure ensure a better nutrients balance when using useful source of nutrition during crop production organic manure contributes the growth of the rhizosphere microorganism and results in better plant productivity. As a result significantly maximum grains yield (11.2 q ha^-1) and straw yield (22.79 q ha^-1) was recorded under FYM @ 5 tons ha^-1. The amount of inorganic fertilizer can be reduced up to 75% by using organic manure without significant affecting of seed yield (Kumar et al., 2016). The yield of crop is in fact the cumulative results of vegetative growth and yield attributes and these are increased by the better supply of nutrients with the FYM treatment which attributed to better nutrient availability, vegetative growth, nutrient transformation and dry matter accumulation during the reproductive phase ultimately in turn improved yield parameters thus increased final grain and straw yield (Sharma et al., 2003 and Singh et al., 2009).
 
Effect of biofertilizer
 
Use of biofertilizers in crop production is cost effective and cheap source of nutrients supply. Most useful and effective for leguminous crop. Legume crops are able to fix atmospheric N through rhizobium bacteria present in the nodules of their roots through the process of symbiosis. The effectiveness of symbiosis depends on the rhizobium strain, the host plant and is influenced by a number of soil and environmental factors (Vincent, 1970). The significantly higher growth parameters was found with B₃- Rhizobium + nutrient mobilizer due to occurrence of rhizobium bacteria a nitrogen fixer microbe and another nutrient solubilizers which solubilised the unavailable nutrient into available form of nutrients. Hence B₃ recorded significantly higher crop growth attributes of black gram crop and also attributed to optimum uptake of N and P. Inoculation of seed with biofertilizer found no significant effect on growth parameters at 20 DAS, while at 60 DAS  significantly higher plant height (48.96 cm), number of branches (4.26), dry matter (9.59 g plant^-1) and CGR (13.48 g day^-1m²) were recorded with B₃- Rhizobium + nutrient mobilizer inoculation treatment and minimum growth attributes was recorded in B₂- nutrient mobilizer treatment and B₁- rhizobium treatment. Nitrogen and phosphate are essential component of all living matters including amino acid, protein, nucleotides and chlorophyll. Combined inoculation of rhizobium + nutrient mobilizer showed higher growth parameters due to synergistic effect. These findings are similar with previous reports of (Gupta et al., 2003). Application of rhizobium + nutrient mobilizer inoculation significantly increased the yield indices such as pod plant^-1 (35.61), grain pod^-1 (5.53), length of pod (4.48) and test weight (40.22) over only inoculate rhizobium or nutrient mobilizer alone. A similar response was also found for plant biomass and grain yield. Simultaneously higher grain yield (10.26 q ha^-1) and straw yield (21.90 q ha^-1) was obtained by B₃- Rhizobium + nutrient mobilizer treatment which was superior over other biofertilizer treatment. Increased nitrogen fixation and production of secondary metabolites by bacteria support plants for efficient energy conversion and more dry matter accumulation; these results were also approved by (Thakur et al., 1999 and Negi et al., 2007) Interactions: The interaction effect between fertilizer, manure and Biofertilizer was observed non significant at 20 and 60 DAS.

Under this experimentation it was concluded that application of NPK @125% RDF (25:56:25 kg ha^-1) + FYM @ 5 tons ha^-1 + Rhizobium + nutrient mobilizer treatment gave maximum growth and yield parameters and yield, but statistically at par growth and yield parameters and yield found in F2- 100 % RDF (20:45:20 kg ha^-1)+ FYM@ 5 tons ha^-1 + Rhizobium + nutrient mobilizer which was found effective for cultivation of black gram with maximum yield for sustainable and economically effective. That as a result of the combined action of organic and inorganic sources of nutrient the improvement in the physical efficiency of various macro and micro nutrients produces high quality and quantity of crops under scrutiny.