Nutrient Use Efficiency in Citrus

Abstract

During the past decades, commercial citrus producers throughout the world have been facing serious challenges including restrictions on water, fertilizer and agrochemical use, potential treats of devastating diseases, and fi erce competitions for global markets. In an era of increased focus on sustainable development, smart technologies, and resource conservation, there has been gradual shift from increasing yield and maximizing pro fi ts to making better use of technical innovations to ensure more ef fi cient use of fi nite resources including land, energy, water, and nutrients. Within this context, it is relevant for scientists to critically re fl ect on how to effectively integrate information related to physiological processes, pedoclimatic conditions, and management practices to increase nutrient use ef fi ciency (NUE) in citrus production systems. Understanding the processes controlling nutrient uptake is critical for development of management practices that enhance NUE while reducing nutrient losses and potential environmental impacts. However, one of the Abstract Citrus production systems are inherently complex, which may hamper ef fi cient resource management. This chapter aims to use a systems approach for structuring more ef fi cient management options for citrus production. It starts by providing a brief overview of production trends in major production regions and outlining the use of a systems-based approach for structuring more sustainable management practices. Starting with the physiological processes and mechanisms controlling nutrient uptake of young seedlings, resource capture and utilization are presented including root growth dynamics and nutrient interception capacity as affected by diurnal crop water use, temperature, and nutrient supply. Uptake processes are scaled-up to a tree level and linked to speci fi c environmental, crop development, and management aspects and integrated into generic conceptual models with special reference to the interactive effects of irrigation and fertility management as related to crop nutrient interception capacity. Then the scope is expanded to look at nutrient management at the fi eld level on an annual basis including tree nutrient allocation, environmental emissions, and development of annual nutrient budgets. In the fi nal section, future perspectives are provided for more effective use of modeling approaches for system design and more costeffective and sustainable resource use. KeywordsNutrient use ef fi ciency • Systems analysis • System design • Resource management • Modeling approaches

Agronomic Responses of Major Fruit Crops to Fertilization in China: A Meta-Analysis

“…In this study, the AE and PFP of perennial fruit crops were significantly lower than those of annual fruit crops (Figures 8 and 10), due to the higher application rate of N, P, and K fertilizer in perennial fruit crops ( Figure 5). Moreover, perennial fruit crops generally had a higher nutrient utilization rate compared to annual fruit crops because the former crops have xylem stored nutrients, prolonged growth and development stages, and dense distribution of roots [66,67]. Thus, the projected AE and PFP of perennial fruit crops in China's fruit crops could be doubled through a decrease of fertilizer input and a yield increase in the future.…”

Soil, Water, and Nutrient Management Options for Climate Change Adaptation in Southern Africa

“…Examples of fertilizer and crop management scenarios have been modeled in Zimbabwe and Kenya (Tittonell et al, 2006, 2007, 2008) and the United States (Ma et al, 2005, 2006; Saseendran et al, 2009, 2010). Such mathematical models may be used to assess the effects of management practices and pedoclimatic conditions on crop water and fertilizer requirements, soil moisture dynamics, crop water and nutrient uptake, and potential nutrient leaching (Scholberg and Morgan, 2012). Robust models that have worked elsewhere and could be calibrated and used for predicting crop yield in several scenarios of agroecologies in southern Africa include the Decision Support System for Agrotechnology Transfer (DSSAT) and its submodels (Jones et al, 2003), the Root Zone Water Quality Model (RZWQM) (Ahuja et al, 2000), and Field‐scale resource Interactions, use Efficiencies and Long‐term soil fertility Development (FIELD) (Tittonell et al, 2010).…”

Integrated Soil Fertility Management in Fruit Crops: An Overview

“…Most of the fruit crops by the virtue of their woody framework (Nutrients locked therein), extended physiological stages of growth, differential root distribution pattern (root volume distribution), growth stages from the point of view of nutrient requirement, and preferential requirement of some nutrients by specific fruit crop, collectively make them nutritionally more efficient than the annual crops (Scholberg and Morgan, 2012). In the backdrop of demography -driven diminishing per capita availability of land (more so in fruit crops), sustaining soil fertility management has gained a greater significance in meeting the multipronged challenges of sustaining the quality production on one hand and ensuring the carrying capacity of soil health on the other hand (Srivastava et al, 2002).…”