Influence of Soil Compaction and Industrial Wastes on Yield and Nutrient Uptake by Wheat and its Residual Effect on Summer Pearl Millet Grown in Loamy Sand Soil

A field experiment was conducted at Agronomy Instructional Farm, C. P. College of Agriculture, S. D. Agricultural University (erstwhile G.A.U.), Sardarkrushinagar during rabi and summer seasons of 2003 to study the “Influence of soil compaction and industrial wastes on yield and nutrients uptake by wheat-pearl millet crops grown in sequence in loamy sand soil”. Total twenty one treatment combinations comprising of seven levels of soil compaction viz., 1.50 (C₀), 1.68 (C₁) and 1.70 (C₂) under dry condition; 1.80 (C₃), 1.85 (C₄), 1.75 (C₅) and 1.83 (C₆) Mg m^-3 bulk densities under wet condition and three levels of industrial wests viz., control (Iw₀), ETP sludge (Iw₁) and fly ash (Iw₂) @ 10 t ha^-1 were tested in a split plot design with four replications. The results of the field investigation indicated that soil compaction treatments of C₄/C₆ increased the grain and straw yield of wheat as well as subsidiary crop of pearl millet. The per cent increase in grain yield of wheat due to C₄ and C₆ levels was 21.3 and 24.3 per cent over control, respectively. Similarly, these treatments also showed residual effects on pearl millet productivity by 23.8 and 14.7 per cent higher over control, respectively. Soil compaction produced beneficial effects on growth and yield attributes of all the three crops. However, it was found significantly superior in obtaining higher plant height, total and effective number of tillers per plant of wheat and pearl millet and test weight of grain of both the crops. Higher levels of soil compaction (C₄, C₆, C₃ and C₅) attained through 4 and/or 8 passes of iron roller at certain moisture content recorded higher content and uptake of nutrients (N, P, K, Ca, Mg, S, Fe, Mn, Zn, Cu) in grain and straw of wheat as well as succeeding crop of pearl millet. As regards the use of industrial wastes, it was observed that incorporation of ETP sludge (Iw₁) significantly increased grain and straw yields both the two crops over by fly ash (Iw₂) and control (Iw₀). The per cent increase in grain yield of wheat and pearl millet due to ETP sludge was 10.1 and 10.9 and that of fly ash was to the tune of 7.8 and 8.0, respectively over control. Industrial wastes enhanced content and uptake of N, P, K, Ca, Mg, S, Fe, Mn, Zn and Cu by grain and straw of all the three crops. Generally, these followed the order ETP sludge>fly ash>control for removal of above ions.