The plant heights of two maize hybrids were influenced by different levels of fertilizers application at harvest of crop were statistically analyzed and presented in the Table 1. The maize hybrid Rajkumar proved superior in respect of plant height, dry matter and leaf are index. The plant height of Rajkumar was significantly higher than that of Sona at harvest stage . Similar result was observed by Bunker et al. (2011). Nutrient Expert and LCC based application of fertilizer produced significantly higher plant height compared to the state recommendation, farmer practices and control treatment. Nutrient Expert^® based application of fertilizer produced significant positive interaction effect between the variety Rajkumar and Sona. Similar result was observed with the dry matter produced per plant with different levels of nutrient management treatments which produce significantly influenced in total dry matter at 90 DAS. All the levels of nutrient management were found to significantly higher than control (no fertilizer application). Results are in conformity with the findings of Paramasivan et al. (2011). The Leaf Area Index of the maize increased steadily up to the 60 DAS and then declined due to senescence of older leaves as the crop progressed towards its maturity. The Leaf area index was significantly increased by the treatment with LCC and Nutrient Expert based application of fertilizer gave the highest leaf area index which was observed at 60 DAS compared to all other treatments and in contest of variety Rajkumar produced higher LAI than Sona. Similar result was observed that the evident that nutrient dose provided by NE and LCC practice fulfills the nutrient requirement of the crop when required hence better growth attributes (Hou et al. 2013 and Singh et al. 2017).

Grain yield recorded at 15% moisture as influenced by varieties and different levels of nutrient management have been presented in Table 2. The grain yield of Rajkumar (38.8 q/ha) variety was significantly higher grain yield than that of Sona variety (31.3 q/ha). This may be due to the superiority of Rajkumar variety over Sona variety with respect to vegetative growth and yield components. Results are in conformity with findings of Bunker et al. (2011).The grain yield was highest when fertilizer application was done based on Nutrient Expert recommendation and it was statistically at par with LCC based application and State recommendation. The percentage increase in grain yield from Nutrient Expert^® based recommendation over control, farmers practices, state recommendation and LCC based application of fertilizer were 126.4%, 30.7%, 3.1% and 1.5% respectively. Similar result was observed by Nottidge, et al. (2011) Like as grain yield, Rajkumar variety produced higher Stover yield of 55.0 q/ha over that of Sona variety (47.7 q/ha) but both the values were statistically at par. However, in case of fertilizer application also observed similar result as in grain yield. The Stover yield was highest (65.9 q/ha) in NE and it was statistically at par with LCC based application and State recommendation. Similar results were reported by Wang et al. (2014). The harvest index doesn't very much in the variety level. The Rajkumar variety recorded maximum harvest index of 41.1 which was statistically at par with f Sona variety (38.9). The fertilizer application through NE recorded highest harvest index (41.3) which was followed by LCC but significantly greater than control. Nutrient expert gave a dynamic adjustment of fertilizer application rates based on crop requirement. Due to the judicious nutrient management under NE based nutrient management practice has led to the higher grain, stover and biological yield over farmer's practice of nutrient management and control. Similar result was observed by Tetarwal et al. (2011); Xinpeng et al. (2014) and Khanal et al. (2017).

The data pertaining to N uptake in maize grain and stover was presented in Table 3. Among the two varieties, higher N uptake in grain, Stover and total N uptake was observed in Rajkumar variety. Among all the nutrient management treatments, the data revealed that the highest N uptake by maize grain (55.4 kg/ha) was recorded in Nutrient Expert which was significantly higher than all other treatments. The highest N uptake by maize Stover (31.3 kg/ha) was recorded in LCC based application of fertilizer and it was at par with Nutrient expert based recommendation. The highest total N uptake by maize (86.3 kg/ha) was also observed when there was LCC based application of fertilizer but it was also at par with Nutrient expert based recommendation. The lowest N uptake (kg/ha) of maize grain (21.2 kg/ha), Stover (19.6 kg/ha) and total N uptake was recorded in control (no fertilizer). The data revealed that the P uptake by maize grain (16.6 kg/ha), Stover (11.0kg/ha) and Total P uptake (27.51kg/ha) was highest in LCC based application of fertilizer which was significantly higher than all other treatments but statistically at par with Nutrient expert based recommendation. Similar result observed in P uptake of grain, stover and total uptake where as the lowest P uptake of Maize grain (6.8 kg/ha), Stover (7.4 kg/ha), and Total P uptake (14.2 kg/ha) were observed where there was no application of fertilizers. The K uptake by maize grain (11.7kg/ha) was highest in Nutrient expert based application of fertilizer. Highest K uptake by maize stover (84.7 kg/ha) and total K uptake (96.1 kg/ha) was observed in LCC based application of fertilizer which was statistically at par with Nutrient Expert recommendation and State recommendation. The lowest K uptake (kg/ha) of Maize grain (4.48 kg/ha), Stover (57.8 kg/ha) and total K uptake (62.3 kg/ha) were observed when there was no fertilizer application. In Rajkumar variety K uptake (kg/ha) of grain (10.7 kg/ha), Stover (80.0 kg/ha) and total K uptake (90.7kg/ha) were significantly higher than the variety of Sona. The higher uptake increased due to better root development which results in better absorption of nutrient which lead to the yield. The uptake response also shows plant metabolic activity earlier reported similar response in nutrient uptake Hou et al.(2013), Khanal et al. (2017) and Singh et al. (2017).

The gross return, net return, and B:C ratio invested have been worked out and presented in the Table 4. The different levels of nutrient management treatments and varieties significantly influenced the gross return, net return and B:C ratio. All the levels of fertilizer application were found to increase the gross return, net return, and return per rupee which was significantly higher over control (no fertilizer application). Nutrient Expert based application of fertilizer recorded the highest gross return of Rs. 66021, highest net return of Rs. 37976 and highest B:C ratio 1.35 which were significantly higher than all other treatments. The lowest gross return (Rs 29912), net return (Rs. 18500) and B:C ratio (0.80) were observed where no fertilizer application and the highest value was observed with Nutrient Expert and significantly highest among all the treatment. Similar result was observed by Wang et al. (2014). Among the two varieties, the Rajkumar variety gave significantly higher gross return, net return , B:C ratio as compared to sona. Due to the productivity of maize was increased under NE and LCC based nutrient management practice which enhence optimum quantity of nutrient applied and also enhance the yield and profit of the crop (Vikram et al. 2015). Similar effects was observed for the varieties effect on the economics as reported by Bunker et al. (2011).

It may be conclude that nutrient management has played an important role in achieving sustainability. The resulted in high price index of chemical fertilizers with their limited production, fertilizer cost, soil health, sustainability and pollution have gave rise to interest in precision nutrient management tools. The values for growth parameter yield, nutrient uptake and economics were significantly affected by different level of nutrient management and varieties. The application of nutrient on the basis of recommendation obtained from the decision support system like “Nutrient expert” and LCC based application proved superior over all other the treatments. Thus, cultivation of Rajkumar variety along with application of fertilizers on the basis of Nutrient expert based recommendation proved better for the cultivation of hybrid maize under lateritic soil of West Bengal.