A good knowledge of possible changes of nutrient stock of a system involves balancing of nutrient input and output in the system (nutrient flow analysis). Nutrient flow analysis using an approach based on “balance” is one of the possible ways to estimate the diversities in the sources and flows of nutrient content of a system (applied fertilizer, fertility in soil, plant mineral uptake and crop residue). It quantifies the whole system management method together with their cost and time. However, nutrient balances involving flows of few nutrient elements are considered “partial balances” because they basically show only a portion of what the farmer takes out of the system and what they put back. Это и многое другое вы найдете в книге PARTIAL NUTRIENT BALANCE STUDIES IN AN INTERCROPPING SYSTEM (SIMON UMEH)