The addition of agricultural by-products to mineral soils has the potential to improve crop production. This study aimed to determine the effects of the readily available sugarcane (Saccharum officinarum) milling by-product bagasse as a soil amendment on yields of sugarcane grown on a sandy Entisol of South Florida. The field trial was conducted on a commercial sugarcane farm for three annual crop cycles (plant cane and two ratoons). Four treatments including 5 cm bagasse (85 ton ha−1); 10 cm bagasse (170 ton ha−1); 10 cm bagasse (170 ton ha−1) plus 336 kg ha−1 ammonium nitrate; and a control (without bagasse and ammonium nitrate) were evaluated. Results indicate that one single application of bagasse increased sugarcane biomass and sugar yield by approximately 23% in the plant cane year. A higher application rate of bagasse (10 cm of bagasse) was recommended since it had a longer effect on increasing sugarcane biomass and sugar yield. Bagasse application enhanced silicon (Si) supply and increased Si plant nutrition. However, the effects of bagasse on the other leaf nutrients were not significant.

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Flooded rice (Oryza sativa L.) in south Florida is grown commercially in rotation with sugarcane and vegetables. From 2008 to 2018, rice production has doubled. During the spring-summer, nearly 200 km 2 of fallow sugarcane land is available for rice production. In 2017, approximately 113 km 2 of rice were planted in the region. The net value of growing rice as a rotation crop far exceeds its monetary return. This study evaluated soil health parameters before and after rice cultivation and compared them against two other common summer farming practices -fallow fields and flooded-fallow. The soil health parameters that were tested as part of this study included soil pH, bulk density, water holding capacity, cation exchange capacity, organic matter, active carbon and nutrient content. Results indicated an increase in soil pH, and a significant reduction in soil bulk density due to rice cultivation. Water holding capacity increased significantly under all flooded land use practices compared to fallow fields. Cation exchange capacity significantly increased when sugarcane fields were cultivated with rice and ratoon rice, nearly doubled from 58 to 101 cmolc kg -1 . Small, yet significant 3% increase in organic matter was observed when sugarcane fields were cultivated with ratoon rice. Almost 16 g kg -1 of active C is being generated within fallow soils, whereas less than half that under flooded practices, limiting the amount of soil loss via oxidation. Based on the soil health index, rice cultivation and flooded-fallow improved overall soil quality compared to fallow lands.

The addition of organic amendments and cover cropping on sandy soils are regenerative farming practices that can potentially enhance soil health. South Florida mineral soils present low soil quality due to their sandy texture and low organic matter (OM) content. Few studies have focused on evaluating the effects of farm-based management regenerative practices in this region. The objective of this study was to evaluate changes in soil properties associated with two regenerative farming practices - horse bedding application in combination with cover cropping (cowpea, Vigna unguiculata), compared to the practice of cover cropping only for two years. The soil quality indicators that were tested included soil pH, bulk density, water holding capacity, cation exchange capacity, OM, active carbon, soil protein and major nutrients (N, P, K). Results indicated no significant changes in soil pH, but a significant reduction in soil bulk density and a significant increase in maximum water holding capacity for both practices. Cation exchange capacity and the amounts of active carbon increased significantly after 1.5-year of the farming practices. Horse bedding application with cover cropping showed a significant 4% increase in OM during a short period. A significant increase in plant-available P was also observed under these two practices. Based on this study, horse bedding application as an organic amendment in conjunction with cover cropping provides an enhanced soil health effect compared to just cover cropping. As local growers explore farming option to improve soil health particularly during the fallow period using regenerative farming practices on sandy soils, these results will assist in their decision making.

Regenerative farming is a common practice adopted to enhance soil health. Routinely, cheaply measured soil health indicators can be used to predict unknown soil health indicators, which makes analysis simple and fast. The objective of this study was to determine the interaction and relationship between soil health indicators and the effects of regenerative farming practices on soil health indicators. We conducted a comprehensive on-farm study across Florida, measuring 11 soil health indicators for 592 soil samples that were collected from the surface 15 cm of soil on 13 experimental sites. Sampled fields were conventionally managed or subjected to either cover cropping, organic amendment application, or their combination, and fallow fields as control plots. We tested the Pearson correlation coefficient between 11 soil health indicators and further tested the types of relationships between each indicator using regression analysis. Strong positive correlations (r ≥ + .5 to 1.0) were obtained, especially between organic matter (OM) with maximum water holding capacity (MWHC), cation exchange capacity (CEC), soil protein (SP), and total Kjeldahl nitrogen (TKN); MWHC with CEC, SP, and TKN; TKN with CEC and SP; total phosphorus (TP) with Mehlich-3 phosphorus (M3P). A strong negative correlation (r ≥ -.5 to -1.0) was observed between bulk density (BD) with OM, MWHC, CEC, and TKN. No significant change in soil health indicators was observed in control plots except for active carbon (AC) and CEC. Organic amendments and a combination of organic amendments with cover crops were effective in improving soil health indicators. However, cover crops alone had no effect on soil health indicators except for CEC and M3K.