A computer-implemented method for recommending agricultural activities is implemented by an agricultural intelligence computer system in communication with a memory. The method includes receiving, over a network, field definition data and environmental data; determining soil data from at least the environmental data; determining, based on at least the soil data, carbon load data indicating carbon load present in the field during a planting date; receiving first input indicating a plurality of starter application criteria; based on the first input and the carbon load present in the field, generating application data that include at least an amount of the starter fertilizer that provides nutrients to seeds throughout a nutrient immobilization period between the planting date and a beginning of a microorganism mineralization period; generating control instructions for controlling an agricultural implement based on the application data.