Examining the Impact of Polyacrylamide and Other Soil Amendments on Soil Fertility and Crop Yield in Contrasting Agroecological Environments

This study aims to investigate the effects of polyacrylamide (PAM) alone or integrated with other soil amendments on soil fertility and Teff (Eragrostis tef (Zucc.) Trotter) yield. A field experiment was carried out for 2 years in three contrasting agroecological zones of the Upper Blue Nile basin, Ethiopia, using a randomized complete block design with 3 replicates. The amendments applied were PAM (40 kg ha−1), biochar (B, 8 t ha−1), lime (L, 4 t ha−1), gypsum (G, 5 t ha−1), farmyard manure (FYM, 5 t ha−1), PAM + B, PAM + L, and PAM + G, and control. The results showed that PAM + L, PAM + B, and L treatments noticeably improved pH, available phosphorus (Pav), total nitrogen (TN), organic carbon, and water infiltration in the Aba Gerima and Guder soils, whereas the PAM + B, B, and FYM treatments expressively increased soil water content, Pav, and TN in the Dibatie soil. Likewise, compared with the control, teff yield significantly (p