Status of Essential Elements in Soil and Grain of Organically Produced Maize, Spelt, and Soybean

Abstract

Organic agriculture offers many benefits through the increased nutritional quality of produced crops, agro-ecosystem preservation, and climate change mitigation. The development of an efficient nutrient management strategy in low-input systems, such as organic agriculture, which supports soil fertility and essential nutrients absorption by crops, is continually exploring. Thus, a study with maize–spelt–soybean rotation during a 5-year period in organic production was established to evaluate the variability in soil organic matter (SOM) and the status of available elements: N, P, K, Ca, Mg, Fe, Cu, Mn, Zn, and Si from the soil, as well as grain yield (GY) and the content of protein, P, K, Ca, Mg, Fe, Cu, Mn, Zn, and Si concentration in the grain of spelt, maize, and soybean. Significant variations in mineral elements in the soil, GY, and grain composition were detected. Spelt achieved the highest average GY, while soybean grain was the richest in a majority of examined nutrients. The soil Ca content was important for GY, while the protein level in grain was generally tied to the Mn level in the soil. It was recognized that soil–crop crosstalk is an important strategy for macro- and micro-nutrients management in the soil and grain of organically produced spelt, maize, and soybean. While a reduction in the GY and protein concentration in grain was present over time, it was established that a low-input system under dry-farming conditions supports nutrient availability and accumulation in grain, under semi-arid agro-ecological conditions of central Serbia.