Effects of integrated application of biological and chemical fertilizers and application method on yield and yield components of maize (Zea Mays L.)

Proper plant nutrition is an important factor in improving product quality and quantity. In plant nutrition, not only must every element available to plants is enough, but respect the balance and balance of nutrients is very important. Over the years with the indiscriminate use of chemical fertilizers, especially nitrogen and phosphorus, and failure to comply with nutrient balance considerable damage to agricultural land and thus entered (Tohidi Moghadam et al., 1386). Beneficial soil microorganisms one of the determinants of plant health and soil fertility, because in several key processes, such as biological control of pathogens, rotation of nutrients and seedling establishment (Rosas et al., 2008). While chemical fertilizers in the last 50 years have had a major role in increasing crop yield but the problems were created which dropped their positive effects and negative outcomes. Although nitrogen is not a limiting resource, but converts atmospheric nitrogen into nitrogen fertilizers requires the use of fossil fuels is limited besides these sources, the cost of production of these fertilizers will also increase (Herzog et al., 2008). Soil microorganisms are important components of the soil system, because not only help to access elements in the soil, but also sticking soil particles and aggregates stability and thereby improves soil structure and reduce vulnerability to erosion (Stamford, 2008). Soil and plant growth promoting bacteria (PGPR) are soil free-living bacteria. These bacteria are often seen near or even inside the plant roots (Rasouli et al., 1382).
In order to study the effects of integrated application of bio and chemical fertilizers as well as application method of biofertilizer on the yield and yield components of maize (Zea maize L.), an experiment was conducted in 2015 in Babol, in a factorial arrangement with completely randomized block design with three replicates. Treatments were integrated application of biological and chemical fertilizers in four levels (chemical fertilizer, ¼ chemical fertilizer biofertilizer, ½ chemical fertilizer biofertilizer, biofertilizer) and biofertilizer application method in three levels (seed inoculation, fertigation and seed inoculation fertigation).
Result showed that integration of biological and chemical fertilizer affected yield and yield components. The highest grain yield was obtained by application of biofertilizers ½ chemical fertilizer. The greatest and lowest harvest indices were recorded in chemical and biofertilizer treatments, respectively. The highest number of grains per ear (41.3) related to treatment (50% chemical fertilizer biofertilizer). The highest 1000 seed weight belonged to treatment (chemical fertilizer biofertilizer) by 394 Biological fertilizer application methods had no significant effect on 1000 grain weight but highest 1000 seed weight were treated with inoculation fertigation by 346.67. The method of application seed treatment irrigation method compared to the other two methods showed more favorable results, although the difference was not statistically significant. Vessy (2003) Stated that biological fertilizer material that has live microorganisms that when the seed, the plant or the soil used in soil or in plant root growth area occupied and plant growth by providing access some essential elements, stimulate. Vessy (2003) also reported that the importance of bio-fertilizers for biological nitrogen fixation by them. This researcher said that with the growth promoting bacteria capable of fixing molecular nitrogen, This consolidation was small and major biological fertilizers through the secretion of growth hormone auxin was especially Which increases the total volume of root hairs Thereby increasing the permeability of the roots and increasing the absorption of nutrients.
The results showed that combined application of these resources while increasing corn yield a significant decrease in the consumption of chemical fertilizers.