Content of mineral matter in the grain of popcorn in a sustainable cultivation system with cover crops

The nutritional properties of popcorn (Zea mays L. ssp everta Sturt.) are very attractive to consumers, making it a highly valuable product with excellent functional properties. The increased percentage of consumption of corn with specific properties is a consequence of its quality, because it belongs to gluten-free food, with a high content of fiber and other important components for human nutrition. In some parts of the world, it occupies a significant part in the diet of the population, while in others it represents a healthy snack. Popcorn is a good source of minerals and is low in calories. The paper examined the content of mineral matter (Ca, Zn) in popcorn (hybrid ZPSC 611k FAO 600) grown in a sustainable system with the use of cover crops (CC) and biofertilizers (BF). The experiment was set up at the Maize Research Institute "Zemun Polje" during 2013/14-2014/15. Cover crops included variants: T1-winter fodder pea, T2-winter oat, mixture T3 - winter fodder pea + winter oat, and control variant T4 - bare soil. CC were sown in autumn, plowed at the end of April or May, after which 1/2 of the plot was treated with BF, and the main crop in both years was winter wheat. Popcorn was sown in mid-May at a density of 65,000 plants per ha. Cover crops in combination with biofertilizer had a significant effect on increasing the content of the examined parameters in the grain, especially in the second year with more favorable meteorological conditions. By comparing the examined years, we observe that the highest Ca content was achieved on the variant with winter fodder pea (313.75 mg g-1) with the application of BF, while the highest values of Zn (58.94 mg g-1) were recorded on the variant with a mixture of winter fodder pea and winter oat without BF in the second year. The results show that winter fodder pea is a good choice as a cover crop, it produces a large biomass, protects the soil and, in combination with biofertilizer, increases the biomass of popcorn and the con