Composted Sewage Sludge Application in a Sugarcane Seedling Nursery: Crop Nutritional Status, Productivity, and Technological Quality Implications

Composted sewage sludge (CSS) contains large amounts of organic matter and nutrients and can be used as an organic fertilizer to improve growth, yield, and quality of sugarcane. However, there is a lack of information regarding the impact of CSS application on sugarcane seedling performance in nursery environments. A field study was conducted using a randomized complete block design to evaluate the development, nutritional status, productivity, and technological quality of sugarcane seedlings after CSS application with or without mineral fertilizer. Morphological variables (stem height, diameter, and number, as well as leaf area), technological attributes (total recoverable sugar: ATR; quantity of sucrose in sugarcane juice: Pol; Brix: percentage (weight/weight) of soluble solids contained in juice; TAH: tons of sugar per hectare), nutritional status, and sugarcane productivity were evaluated. Treatments did not influence morphological and technological variables except for TAH but did positively alter nutritional status and seedling productivity. The application rates of 5.0 and 7.5 Mg ha(-1) of CSS with or without mineral fertilizers (MF) provided the greatest increase in crop productivity. Our results indicate that CSS can be a sustainable nutritional management option in sugarcane seedling nurseries, resulting in greater crop productivity at lower mineral fertilization rates.