The effect of compaction stresses and soil gypsum content on the growth and yield of millet

الملخص

A field experiment was carried out in soil columns during the spring season of 2021 at the research station of the College of Agriculture/ Tikrit University, for the purpose of studying the effect of compaction stress and the soil gypsum content on the growth and yield of millet. The experiment included two factors, the first was soil content of gypsum and included 96, 163, 218 and 264 and 371 gm kg^-1. The second was compacting the soil to apparent densities of 1.2,1.3, 1.4, 1.5,1.6 and 1.7 mega gram m^-3. The compacted soil columns were planted with millet (panicum spp) at a rate of (5) Seeds in each column on 7/6/2021, and I thinned the plant to (3) plant in each column. To study the effect of compaction of soils with different gypsum contents, with the aim of determining the critical limit for the degree of compaction of gypsum soil on root penetration, growth, and yield of millet. The millet crop was planted and the experiment was irrigated based on the evaporation basin, and the amount of water added to each column was calculated until the crop was harvested on 11/5/2021. The level of compaction (1.2) mega gram m^-3 gave the highest average plant height (45.3) cm, dry weight of roots (2.40) g pot^-1, and grain yield (3.00) gm pot^-1. When compaction increased, these characteristics began to decrease, and the level of compaction was recorded as (1.7). mega g m^-3 .The lowest average was (28.70) cm (1) g ace^-1 (1) g ace^-1, respectively. Excess gypsum had a negative effect on the growth characteristics and yield of millet plants, as soil with a gypsum content of (96) g kg^-1 gave the highest average plant height (39.80) cm, dry weight of shoots (25.60) g per pot^-1, and grain yield (2.60) g. Pot^-1, while the soil with gypsum content (371) g kg^-1 gave the lowest average of (35.80) cm, (22.40) g pot^-1, and (1.70) g pot^-1.