BONUS SPRING SUMMER 2025

The use of NutriCAST™ in row crops The measured nutrient (N and K) fraction released is presented cumulatively as a percen- tage of the total element released at the end of 240 days. Although N is present in both the nitrate (NO 3 ) and ammonium (NH 4 ) form, the nitrate fraction represents approximately 1% of the total N in NutriCAST™ (data not shown). Nitrogen is mostly in the ammonium (NH 4 ) form, and nearly all of the ammonium is available for plant use within 28 days (Figure 1). However, the form of N (ammonium or nitrate) depends on a number of processes that happen during the composting process, including mine- ralisation, nitrification and denitrification, which again depends on the local environmental conditions, e.g. temperature, pH, oxygen, water content and the type of organic material. 3 On the other hand, 80% of the total K is plant available after 60 days, and the rest (20%) is slowly released over 180 days (Figure 1). PLANT NUTRITION NutriCAST™ for healthy soils From the very birth of the concept Soil Health in 1909( 1) , it was recognised that soil fertility not only refers to the nutrient status of soils, but also includes the carbon content and abun- dance and diversity of organisms in the soil. NutriCAST™ is registered as a Group 2 fertiliser and therefore regulated by the Fertilizers, Farm Feeds, Seeds and Remedies Act, Act 36 of 1947. NutriCAST™ consists of a mixture of composted animal manure and earthworm casts and its manufacturing is also regulated by the National Environmental Management Act, Act 107 of 1998. Nutrient content The nutrient content of NutriCAST™ is typically in the range of 1,8% for nitrogen, 1,3% for phosphorus and 2,5% for potassium. The re- lease of nitrogen (NH 4 and NO 3 ) and potassium (K) from NutriCAST™ over time is presented in Figure 1. NutriCAST™ is registered as a Group 2 fertiliser and therefore regulated by the Fertilizers, Farm Feeds, Seeds and Remedies Act (Act 36 of 1947). NutriCAST™ consists of a mixture of composted animal manure and earthworm casts and its manufacturing is also regulated by the National Environmental Management Act (Act 107 of 1998). Nutrient content The nutrie t content of NutriCAST™ is typically in the ra ge of 1,8% f r nitrogen, 1,3% for p osphorus and 2,5% for potassium. The release f nitr gen (NH 4 and NO 3 ) and potassium (K) from Nu iCAST™ over time is presented in Figure 1. The measured nutrient (N and K) fraction released is presented cum latively as a percentage of the tot l lement released at the end of 240 days. Alth ug N is present in both the nitr te (NO 3 ) and ammonium (NH 4 ) form, th nitrate fraction represents approxi ately 1% of the total N in NutriCAST™ (data not hown). Nitr gen is mostly in t ammonium (NH 4 ) form, and nearly all of the ammonium is available for plant use within 28 days (Figure 1) . However, the form of N (ammonium or nitrate) depends on a nu ber of processes that happen during the composting process, including mine- ralisation, nitrification, and denitrification, which gain depends on the local environmental conditions, e.g. temperature, pH, oxygen, water content, and the type of organic material.2 O the other hand, 80% f the total K is plant available after 60 ays, and the rest (20%) is slowly rele sed over 180 days (Figure 1). NutriCAST™ for h l ils From the very birth of t il ealth in 1909 1 , it r c is t at soil fertility not only refers to the nutrient status of soils, but also includes the carbon content and abundance and diversity of organisms in the soil. www.agribonus.co.za Spring/Summer 2025 BONUS 65