Effect of Soil Salinity and Compaction on Nitrogen, Phosphorus and Potassium Uptake by Wheat

The long-term use of heavy-weight agricultural machinery has caused extensive compaction in soils, while information about soil compaction effects on growth and yield of crops in saline soil is scanty. To study the interactive effect of soil compaction and salinity on macronutrient elements uptake by wheat grain, a factorial pot experiment was conducted on loamy soil, arranged in randomized complete block design with three replications. The treatments were two levels of soil salinity (saline and non saline) and five compaction levels (0, 5, 10, 15, 20 percent of compaction). Different compaction levels were achieved at 15% moisture level by dropping 2 kg weight, controlled by tripod stand, from 0.3 m height inside the soil filled pots. Natural saline water was used to provide the desired salinity level of soil (6 dS m-1).The amount of grain nitrogen, phosphorus and potassium were measured and statistically analyzed. The results showed that the soil compaction significantly (p<1%) decreased uptake of N, P, K in grain wheat. Salinity decreased the amount of N, P, and K in grain significantly at %5, %1, and %1 levels, respectively. Also, the interactive effect of soil compaction and salinity on the amounts of nitrogen and potassium was significant at %1 level, i.e. the amount of nitrogen and potassium decreased with the increase in soil compaction in saline treatment, however, this interactive effect on grain P was not significant.