Residual Effect of Foliar Application of Nano Fertlizers and Organic Source of Nitrogen on the Productivity and Economics of Zero Tilled Green Pea in Rice-green Pea Cropping Sequence

Green pea (Pisum sativum L.) is one of the important pulse crop of the Fabaceae family, which ranks fourth in the economic importance of the Fabaceae family and comes in second place after the tomato crop as raw material for canning factories. It is an annual herbaceous plants  limited or unlimited growth and adapted to wet climatic conditions. Pea are grown for their  fresh green seeds or dry seeds and sugary pods, it is consumed as cooked or canned or frozen  food, it is a vegetables rich in protein and carbohydrates and nutrients, on the agricultural side  pea production plays an important role in the agricultural cycle as it is a crop that contributes  to the stabilization of atmospheric nitrogen and improves soil fertility. After rice harvest, the majority of farmers in Manipur leave their land fallow without planting anything, despite the  fact that it has a great deal of potential for growing a second crop in the rabi season with the  remaining moisture and nutrients. One of the most crucial options for Manipur’s farmers is  green pea, which not only boosts their revenue but also makes use of the nutrients and residual moisture in the soil. The current fertilizer application system ignores the carryover effect of  the manure or fertilizer applied to the previous crop and instead bases its decisions on the  nutritional requirements of the specific crop. The development of nanotechnology has made it possible to mass-produce metal nanoparticles that are physiologically important, which can be  utilized to improve fertilizer formulations for improved uptake in plant cells and nutrient conservation. Additionally, nano fertilizers can lessen nutrient losses through leaching, enhancing the effectiveness of nutrient use while addressing environmental issues brought on  by the extensive use of fertilizer (Raliya et al., 2016). Targeted delivery and controlled or slow  release mechanisms in nanostructured fertilizers can increase the efficiency of nutrient usage. They could precisely release their active substances in response to biological needs and  environmental cues. Additionally, through accelerating the rates of photosynthesis, seed  germination, seedling growth, carbohydrate and protein synthesis and nitrogen metabolism, nano fertilizers have shown improved crop productivity (Solanki et al., 2015). According to Hedge (1998), applying organic sources of nutrients to the previous crop greatly benefits the  following crop. In light of the aforementioned considerations, an experiment was set up to determine whether the foliar application of nano fertlizers and organic source of nitrogen in  the previous kharif rice crop had any lasting effects on the productivity of the following green  pea crop.

Growth parameter
 
The pooled data in Table 1 showed that the different foliar applications  of nano fertilizers and organic nitrogen sources utilized in the previous kharif rice had a  residual effect on the green pea’s growth characteristics. The application of nano NPK  (19:19:19) @ 1.5% resulted in the highest plant height (40.50 cm), which was statistically  higher than all other treated plots. This was followed by the application of nano NPK @ 1% (34.30 cm) and nano NPK @ 0.5% (31.44 cm) and lowest was observed in control plot (19.34 89 cm). It might be due to reducing nutrient leaching and improving nutrient use efficiency, which releases nutrients gradually over a longer period of time. This can help conserve nutrients in  the soil for succeeding crops. This finding was similar to (Raliya et al., 2016).
 

       
With regard to organic source of nitrogen, green pea plots receiving a combination of nano NPK fertilizers and organic sources of nutrients, such as vermicompost, showed the highest  development features (Table 1). The application of vermicompost @ 100% RDN recorded a 95  vermicompost @ 50% RDN (29.47 cm). It might be due the application of vermicompost provided the highest availability of N, P, K and organic carbon in soils on soil sampling (after harvesting rice), helping to provide the best direct and residual effect on the availability of soil  nutrients, plant nutrient uptake and soil enrichment of the rhizosphere with micro and  macronutrients. A similar trend was found in (Nurhidayati et al., 2018).
       
The subsequent green pea crop’s plant height was significantly influenced by the interactions  between nano NPK and organic source of nitrogen used in kharif rice. The interaction between several NPK and organic source of nitrogen used in the prior kharif rice crop, on the  other hand, had a substantial influenced on the crop growth rate of green pea (Table 1). The  interaction between foliar application of nano NKP @ 1.5% + vermicompost @ 100% RDN, (N₁F₄) with a value of (42.59 cm) recorded the highest plant height among the various  treatment combinations The lowest plant height was recorded in control + vermicompost @ 50% RDN (17.45 cm). The accumulation of more nutrient residues that were made available  to the succeeding crop may have led to better crop growth characteristics of green pea. This  may have occurred through the mineralization of organic manures i.e vermicompost or the  solubilization of nutrients from native sources during the process of decomposition.
 
Yield attributes
 
The no. of pods/plant, pod length (cm) and no. of seeds/plant in the  following green pea crop significantly increased as a result of various nano NPK fertilizers  and organic source of nitrogen (Table 2). The pooled data revealed that application of nano  NPK @ 1.5%, recorded maximum no. of pods/plant (3.27), pod length (cm) (9.26cm) and no.  of seeds/plant (8.57) which was comparable with the plot receiving nano NPK @ 1% and nano NPK @ 0.5%, respectively but they were significantly higher than control plot. The  lowest no. of pods/ plant (1.40), pod length (cm) (6.51) and no. of seeds/plant (4.9) were also  observed in control plot.
 

       
The pooled data in Table 2 showed that among the various sources of organic nitrogen, the  plot receiving vermicompost @ 100% RDN had the statistically highest no. of pods/plant  (2.73), pod length (cm) (8.49) and no. of seeds/plant (7.55) while the plot receiving 50% RDN (N3) had the least residual effect on no. of pods/plant (2.20), length (cm) (7.73) and no.  of seeds/plant (6.47).  This might be due to the application of vermicompost enhanced the  physical, chemical and biological characteristics of the soil, contributed plant development  factors and had a favorable impact on the production of dry matter both directly on the first crop and indirectly on the second crop. Application rate and quality both affected the residual effect of vermicompost, so the higher the rate of application, the more residual effect should  be on the soil. Hence, it had a positive effect on the vegetative growth of the plants and  improved the yield of crops. Similar findings were reported by Jat and Ahlawat (2004) and Atiyeh (1999).
       
The no. of pods/plant, pod length (cm) and no. of seeds/plant in the following green pea crop were significantly affected by the interaction between nano NPK and organic source of nitrogen (Table 2). The interaction between foliar application of nano NKP @ 1.5% + vermicompost @ 100% RDN, (N₁F₄) recorded the highest no. of pods/plant, pod length (cm)  and no. of seeds/plant among the various treatment combinations. The lowest no. of 50% RDN Table 2.

Yield
 
Table 2 makes it clear that the various foliar applications of nano NKP fertilizers and  organic source of nitrogen used in the prior kharif rice crop had a considerable lasting  residual effect on the production of the following green pea crop. Higher green pod yield was  achieved in the plots receiving F₄, or nano NKP @ 1.5% (4131 kg/ha), F₃ i.e. nano NKP @ 1% (3612 kg/ha) and they were significantly difference with one another. F₁ or control plot  (2030 kg/ha) gave considerably decreased green pod yield across the treatment plots.  Application of nano-NPK fertilizers, alternatively, decreased soil pH and EC while  increasing soil organic matter and N, P, K, Fe, Mn and Zn concentrations. The findings  unmistakably show that the green pea’s pod yield and nutritional value were boosted by the nano-fertilizer. As a result, our study has demonstrated that nano fertilizers release nutrients  gradually, increasing soil fertility and improving green pod yield. Similar finding was also  reported by El-Sayed et al., (2020).
       
The plot receiving N₁, which was application of 100% RDN (3567 kg/ha), had the highest green pod yield among the various organic source of nitrogen and that was followed by N₂, i.e application of vermicompost @ 75% RDN (3212 kg/ha). The lowest green pod yield was obtained with 50% RDN application (N₃), which resulted in yields of (2978 kg/ha) (Table 2). This could be owing to the vermicompost’s microbial stimulation and the N given through  slow mineralization. Hence application of vermicompost significantly improved the soil  chemical properties such as pH, electrical conductivity, organic matter and nutrient status and  resulted in better plant growth and yield (Senthamizhkumaran et al., 2021 and  Nagavallemma et al., 2004).
       
The green pod yield of the succeeding green pea crop was significantly affected by the interactions between the various foliar applications of nano NKP fertilizers and organic  source of nitrogen (Table 2). The interaction between foliar application of nano NKP @ 1.5% + vermicompost @ 100% RDN, (N₁F₄) recorded the highest green pod yield among the various treatment combinations, with a total of (4761) kg/ha. The green pod yield with the  lowest value (1881 kg/ha) was observed in control + vermicompost @ 50% RDN.
 
Economics
 
The pooled data in Table 3 revealed that the foliar application of nano NKP @ 1.5% + vermicompost @ 100%RDN (N₁F₄), gave the highest gross returns (Rs.238073), net  returns (Rs. 213373) and B:C ratio (8.6), respectively followed by the treatment combination of N₂F₄ i.e nano NKP @ 1.5% + vermicompost @ 75% RDN ( Rs. 199535), (Rs. 174835)  and (7.1) and N₁F₃  i.e nano NKP @ 1% + vermicompost @ 100% RDN (Rs.185025), (Rs.  160325) and  B:C ratio of (6.5). The N₃F₁ plot, which was given 50% RDN through  vermicompost + control, produced the lowest gross returns (Rs. 94082), net return (Rs. 69382) and a B:C ratio of (2.8). Higher net returns and a better B:C ratio might have been caused by the production of more yield in combination with a higher market price for greenpea seeds. The outcome of Ajithkumar et al., (2021) is consistent with the outcomes of  this study.
 

The use of nanotechnology in agriculture is still in its infancy. However, it has the ability to  completely transform agricultural systems, particularly when it comes to concerns about the use of fertilizer. Application of nanofertilizers encouraged green pea growth, development and has the potential to enhance crop productivity and plant nutrition. On the other hand,  applying organic sources of nutrients to the previous crop greatly benefits the following crop by improving the availability of N, P, K and organic carbon in soils, helping to provide the best direct and residual effect on the availability of soil nutrients, plant nutrient uptake and  soil enrichment of the rhizosphere with micro and macronutrients, so the higher the rate of  application, the more residual effect should be on the soil. The results of this study will be  useful for future investigations into the use of vermicompost and nanotechnology in  agriculture.