Impact of agronomic practices on physical surface crusts and some soil technical attributes of two winter wheat fields in southern Iraq

Abstract

Purpose Agricultural management as tillage systems and manure application can contribute effectively to controlling physical surface crusts (SCs), improving the soil’s technical characteristics and germination rates. While agronomic practices are generally applied to winter wheat fields in southern Iraq, no previous study has explored their impact in combination with SCs and soil physical attributes on wheat productivity (WP) under different soil textures. Materials and methods The impact of different agronomic management practices on the formation of soil physical surface crusts (SCs), soil compaction (measured by soil penetration resistance, SPR), soil volumetric water content (VWC), soil bulk density (ρb), mean weight diameter of aggregates (MWD), and WP was examined in two soil textures (clay loam, clay) during 2020 and 2022. Experimental data were subjected to an identical and randomized complete block design (RCBD) under a nested-factorial experimental design, where nine treatments with three replicates each were selected. This included three tillage practices (conventional tillage system (CT), till-plant (TP), and rotational tillage (NTCT)), alongside a sub-treatment with organic fertilizers (cattle manure (CF), and wheat straw (WR)), or without added fertilizer (WT). Results and discussion Results showed that CT treatment increased SCs during wheat growth stages by significantly increasing aggregate stability. A significant difference in ρb and SPR and a higher distribution of VWC were seen under CT treatment when compared to TP and NTCT treatments. TP treatment showed a significantly increased in SPR and ρb, particularly in clay loam. The MWD under TP and NTCT was significantly different to CT treatment, which may be explained by an increase in soil stability due to their management practices. Additionally, both organic fertilizers (CF and WR) significantly enhanced SCs, SPR, VWC, ρb, MWD, and WP. Conclusions These data showed a strong relationship between SCs and ρb and between VWC and SPR, which are directly affected by the soil’s water content.