Sustainable Nutrient Management in Sugarcane Fields

The state of sugar in Indonesia which is decreasing in terms of production, the imbalance between production and consumption, can occur due to two things, both on-farm and off-farm. Planting in monoculture for a long period of time will cause reduced soil fertility conditions so that sugarcane productivity decreases. Sustainable nutrient management in sugarcane plantations is an effort made to obtain optimal and profitable productivity, while still trying not to damage the environment so that it can be sustainable and its productivity can be maintained in the long term. Several concepts for sustainability have been put forward by many experts, including the use of site-specific fertilizers, maintaining soil fertility by using sugar processing by-products and the use of humic. It is hoped that some of these application methods can maintain sugarcane plantations to be sustainable.

Physiology of Nitrogen and Calcium Nutrition in Blueberry (Vaccinium sp.)

Sustaining the fourfold increase in blueberry (Vaccinium sp.) production witnessed during the previous two decades requires better understanding of its mineral nutrient physiology. The primary goals of this review are to evaluate our current understanding of the physiology of nitrogen (N) and calcium (Ca) nutrition in blueberry. Nitrogen concentration in blueberry ranges from 0.4% to >2% across organs. Blueberry uses N in various forms (organic and inorganic), but it appears to display preference for ammonium (NH4+) over nitrate (NO3−). The roles of N acquisition, translocation and assimilation in determining N-source preference in blueberry are evaluated. Calcium plays important roles in determining fruit quality owing to its function in maintaining cell wall and membrane integrity. It is unique in its translocation characteristics being transported primarily via the xylem. Fruit [Ca2+] typically declines from around 0.2% during early development to <0.05% at ripening. Modes of Ca acquisition and transport to the fruit, and various approaches to improve fruit [Ca2+] are discussed. Areas where further research is warranted to improve our understanding of N and Ca physiology in blueberry are identified. Such knowledge is essential for sustainable nutrient management, improving productivity, and enhancing fruit quality in blueberry.

Zeolite and Vermiculite as Inorganic Soil Amendments Modify Shoot-Root Allocation, Mineral Nutrition, Photosystem II Activity and Gas Exchange Parameters of Chestnut (Castanea sativa Mill) Plants

One of the most challenging topics for the sustainable agriculture is how to decrease high fertilization rates. A pot experiment, exploring the effects of zeolite (ZEO) and/or vermiculite (VER) as soil amendments, comparing to the soil application of a controlled release fertilizer (CRF), was realized in chestnut plants. Various parameters related to soil fertility, and plant growth, nutrition, and physiology were investigated to gain knowledge towards more sustainable management. After ZEO application and in comparison to CRF, an impressive boost in soil K was achieved. Moreover, soil P and Zn levels were higher in the VER-treated soil, compared to CRF. Leaf K and Ca concentrations were significantly higher in ZEO, compared to the VER treatment; the highest foliar N and Zn concentrations were measured in CRF and VER, respectively. However, significantly lower foliar Mn and Cu were found in VER. The highest root biomass produced in the ZEO treated plants. For most nutrients, their total uptake per plant was higher in CRF and ZEO. Finally, photosynthetic rates were higher in VER (mainly due to non-stomatal factors) and CRF (mainly due to stomatal factors). Our data open a discussion towards the application of ZEO and/or VER as soil amendments in chestnut nurseries and orchards, aiming at partially decreasing fertilization rates and boosting sustainable nutrient management.

Implementing the Five Rs of Nutrient Stewardship for Fertigation in Florida’s Vegetable Production

The five Rs of nutrient stewardship is a mnemonic device used to emphasize accuracy and precision for nutrient management so as to apply the (1) right source of fertilizer at the (2) right rate at the (3) right time in the (4) right place with the (5) right irrigation. Because the majority of Florida's soils are sandy, this fifth R is imperative for sustainable nutrient management for commercial crop production. These main points of nutrient management (source, rate, time, place, irrigation) may help enhance sustainability by reducing pollution by eutrophication, nitrogen loss through ammonia volatilization, and climate change from soil greenhouse gas emission. This new 8-page publication of the UF/IFAS Horticultural Sciences Department was written by Mary Dixon and Guodong Liu.https://edis.ifas.ufl.edu/hs1386