WATER RETENTION ADJUVANT IN SOIL AND IT EFFECTS IN MYCORRIZHAL COLONIZATION IN SOYBEAN

The microorganisms of the soil are responsible for many ecological services in agricultural ecosystems, therefore it is important to observe the edaphic microbiota answers to the management practices adopted and inputs used in agriculture. The raise in obtaining nutrients and other benefits are attained by the plants by means of symbiotic assimilation with arbuscular mycorrhizal fungi (AMF). However, the benefits exploited of the arbuscular mycorrhiza (AM) in agriculture have been impaired by agricultural practices that dimes the number of mycorrhizal propagules in soil, the mycorrhizal colonization in the roots and the diversity of species of AMF. Knowing that the AM is beneficial for the agricultural productivity added to the fact that the AMF is being considerate an important bioindicator of the quality of the soil becomes indispensable to know the effects of the agricultural inputs in the mycorrhizal inoculum potential in agricultural areas. In this context, the present work had as objective to evaluate in field conditions in soil application of adjuvant commercially sold that retains water under the colonization of soybean roots by AMF. The essay was conducted in the 2017/2018 crop on a soybean crop area next to the city of Maringá, Paraná, Brazil, that has sandy soil. Were established four treatments (control group, recommended manufacturer dose, half dose and one and a half dose in relation to the recommendation) and four repetitions. It was observed that the application of increasing doses of the adjuvant did not affect the percentage of mycorrhizal colonization on soybean roots in a significant way, being the values of percentage in control group, half dose, recommended dose and one and a half dose were 52%, 61%, 60% and 66% respectably. The results suggest that, opposed to agricultural inputs like chemical fertilizers and agrochemical, which reduces the mycorrhizal inoculum potential in soil, the retention adjuvant did not affect in a negative way the AMF community. Although, besides the mycorrhizal colonization, others parameters related to the AMF community, like the diversity of AMF species and the abundance of spores have also to be analyzed and for a longer period in order to obtain more precise results about the effects of this product in the AMF community in the soil.