Impact of different forms of corn biomass on soil physical properti̇es

Soil organic matter plays a decisive role in plant growth by directly affecting the soil's physical, chemical, biological, and mechanical properties. Increasing soil organic matter content, which is low, improves soil deterioration while also increasing its resistance to degradation. It also contributes to ecosystem sustainability by ensuring soil carbon storage. This study used different biomasses from maize, a plant grown in many regions of our country. In maize cultivation, post-harvest residue is recycled back into the soil to support soil organic matter levels. Another significant aspect of the study is the use, for the first time, of the green parts of maize, which has high biomass production potential, as a soil conditioner and/or amendment. For this purpose, three different forms of maize biomass (compost, maize straw, and maize green parts (silage)) were used as organic soil amendments. The study covers two different periods of silage maize and barley cultivation. In the study, three different forms of maize biomass were applied at 1, 2, and 4 of the maize da-1 at 0-20 cm soil depth in a randomized block design with four parallel plots. During this process, soil pH, EC, liquid limit, plastic limit, plasticity index, water retention curves, field capacity (TK), wilting point (SN), available water capacity (FSK), porosity (P), air-filled pores (HDG), bulk density (Pb), penetration resistance (PD), least limiting water range (LLWR), hydraulic conductivity (K) under saturated conditions, and plant root fresh and dry biomass were examined in detail. Analyzes based on the obtained data revealed statistically significant differences in both the type of maize waste applied and the dose levels. Applications at a dose of 4 t da⁻¹ were particularly effective in improving soil properties, and compost material applied at this dose demonstrated more significant remedial effects compared to other application types. In the first year of maize production, plant fresh root weight increased by 129.2% compared to the control with the 4 t da⁻¹ compost application, and dry weight increased by 100.8% compared to the control with the 4 t da⁻¹ straw application. During the barley production period, dry weight increases of 21.3% and 45.8% were measured in the straw and compost applications, respectively, compared to the control. The highest increases in liquid limit values compared to the control were observed in the straw application at 4 t da⁻¹ (10.96%) in the first year, and in the green parts application at 4 t da⁻¹ (6.2%) in the second year. Pb values decreased by 6.95% in the first year with the 4 t da-1 green parts application, 13.72% in the 4 t da-1 compost application, and 12.84% in the 4 t da-1 straw application in the second year, respectively, in the compacted and uncompacted areas compared to the control. Ks values increased the most compared to the control with 66.03% in the first year with the 4 t da-1 compost application, and 63% in the 4 t da-1 straw application in the second year. Compost, straw, and green parts applications, respectively, increased soil water holding capacity, improved water conductivity, and reduced compaction resistance, thus increasing LLWR values. Thus, in addition to increasing agricultural productivity, positive results were also demonstrated in terms of the sustainability of soil health. Keywords: Compost, maize green parts, least limiting water range, maize green parts, organic matter, penetration resistance, straw