Growth and development of corn plants depending on the use of straw and green manure crops

The regularities of the growth and development of corn plants of hybrids NK Thermo and NK Lemero according to the use of straw together with the green manure crops in the conditions of the Western Forest-Steppe are theoretically justified. The maximum use of the organic mass of plant residues, other secondary products of agriculture and plant growing, green manure crops is now becoming an effective and reliable reserve for the provision of soil in the conditions of the Western Forest-Steppe by organic substance, an essential material for soil formation, in particular the accumulation of humus and essential nutrients for plant nutrition and soil microorganisms. The works were carried out during 2013‒2015 on the experimental field of the branch of planting and selection department of the Podilskyi State Agricultural and Technical University in the private firm “Bogdan and K” in the Sniatynskyi district of the Ivano-Frankivsk region (western part of the Forest-Steppe). The biological preparation Vermistym-D (6 l/ha) was used for decomposition of straw and plant residues. In all variants, where the decomposition of straw was carried out, a solution of 10 kg/ha of carbamide was added to the destructor. White mustard as green manure crop was sown at a rate of 3 million of germinable seeds per hectare, oil radish ‒ 2.5 million of germinable seeds per hectare, mixture of white mustard ‒ 1.8 million of germinable seeds per hectare and oil radish ‒ 1.5 million of germinable seeds per hectare. The hybrids of corn NK Thermo and NK Lemero were sown with the norm of 80 thousand of germinable seeds per hectare. The combined application of straw and green manure crops in the experiments carried out significantly influenced the agrophysical, agrochemical properties of the soil and its biological activity. In particular, with respect to control, the number of blocky (<10 mm) and small (<0.25 mm) fractions decreased, respectively, on 8.9‒9.3% and 9.0‒9.2%, and the content of agronomic-valuable aggregates (0.25‒10 mm) on 3.0‒4.6%, the density of the sowing layer of soil was on 0.08‒0.10 g / cm3 less than in the control. At the time of sowing, corn porosity in the soil layer of 0‒10 cm in relation to the control was recorded at 6.1‒9.9% higher in all variants of combined application of straw and green manure crops. According to research results was determined, that the carring out decomposition of straw by Vermistym-D with the subsequent sowing of green manure crops significantly improved the agrophysical properties of soils, reduced the loss of moisture in the arable layer, which undoubtedly affected the field germination rate of the seeds and the density of plant stand. In all variants, the field germination rate was larger on 3.6‒4.8% and the number of plants per hectare in the phase of full seedlings was larger on 2857‒3710 pieces in relation to the control. Before harvesting, the survival rate of the plants was registered on 1.1‒3.0% higher compared to the control. The highest parameters were in the variant where the straw was decomposed by the preparation Vermistym-D at the dose of 6 l/ha, in combination with the sowing of the mixture of green manure crops (white mustard and oil radish). At the same variant, the height of plants of the hybrid NK Thermo was higher in the phase: the seedlings ‒ 6‒8 leaves on 4.4 cm relative to the control, heading of panicles – on 19 cm, complete ripeness ‒ on 21 cm relative to the control. For the growing of the maize hybrid NK Lemero, these indicators in accordance with phases grew in the same proportion slightly better. The results obtained with respect to the rates of linear growth of corn plants, the formation of their overall height, give the grounds to confirm, that the green unguimized mass of green manure crops and straw during the growing of the culture provided better soil conditions of the hydrophysical state and plant nutrition.