**6. Conclusion**

Achievement and maintenance of high nutrient use efficiency (NUE) together with high crop productivity have become a major challenge in both developed and developing countries with an increasing growing population, depletion of natural

*Toward the Recent Advances in Nutrient Use Efficiency (NUE): Strategies to Improve… DOI: http://dx.doi.org/10.5772/intechopen.102595*

resources, and deteriorating environmental conditions. Improving nutrient use efficiency (NUE) in plants is vital to enhance the yield and quality of crops, reduce nutrient input cost and improve soil, water, and air quality [3]. Higher NUE by plants could reduce fertilizer input costs, decrease the rate of nutrient losses, and enhance crop yields. Improving crop nutrient use efficiency ideally requires an understanding of the whole system, from the macro (agro-ecosystem) to the molecular level.

The development of nutrient-efficient crop varieties that can grow and yield better with low supply is a key to improving crop production. A prerequisite for nutrient use efficiency for any germplasm will be the optimization of agronomic practice for any given environment and season. Judicious application of fertilizer that includes the right rate, right time, right source, right place, and balanced fertilization (4RB) is the best management practice for achieving optimum nutrient efficiency. By the coordination of the acquisition, root-to-shoot translocation, utilization, and remobilization of internal Pi can be achieved through genetic breeding. Selection and breeding nutrient efficient species or genotypes within a species are justified in terms of reduction in fertilizer input cost of crop production and also reduced risk of contamination of soil and water. Overall NUE in plant is a function of capacity of soil to supply adequate levels of nutrients and ability of plant to acquire, transport in roots and shoot, and remobilize to other parts of the plant. Improvement in NUE will ultimately come from integrating a range of different approaches to develop a more efficient farming system. Use of nutrient efficient crop species or genotypes within species in combination with other improved crop production practices offers the best option for meeting the future food requirements of expanding world populations. Modern tools and resources available to plant scientists and the agronomy and breeding communities should aid further improvements in NUE and hence crop production. Therefore, integrated strategy that seeks to increase phosphorus use efficiency and simultaneously seeks to recover unavoidable phosphorus losses. The nutrient inputs in the intensive farming system should be optimized to achieve both high crop productivity and high nutrient use efficiency through maximizing root/rhizosphere efficiency in nutrient mobilization and acquisition.
