Browsing by Author "Ahmad, Muhammad Rashid"

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    Effect of sulphur fertilization on growth and chemical composition of sorghum (Sorghum Bicolor L.) and on utilization of sorghum silage fed to wethers
    Ahmad, Muhammad Rashid (Virginia Tech, 1991-05-24)
    Sulphur (S) is an essential element for plant and animal nutrition, but widespread deficiencies of S occur world wide. Current recommendations for nitrogen (N):S ratios are 15 to 18:1 and 10 to 12:1 for plant and animal nutrition, respectively; but recent information suggests these may not predict animal response. Sorghum is an important crop, particularly in drier climatic regions but little is known concerning S-nutrition for sorghum growth or utilization of S-fertilized forages. Sorghum "Pioneer 947" was grown on a Lucy loamy sand (loamy, siliceous, thermic Arenic Kandiudult) in King William County, VA, with and without S fertilization (0 vs. 138 kg S ha⁻¹ as ammonium sulphate) in a randomized block design with four replications. Sulphur fertilization decreased (P < 0.05) soil pH and increased soil S in the 0 to 25 cm (P < 0.08) and 25 to 50 cm (P < 0.05) soil layers. An increase in Mehlich-I extractable soil P, Mn (P < 0.05) and soil N0₃-N (P < 0.06) at surface 25 cm layer occurred with S-fertilization. At harvest, S-fertilization increased (P < 0.05) S and water soluble carbohydrates and decreased (P < 0.05) N:S ratio and P concentration in whole plants. Sorghum leaves were higher (P < 0.05) in N, S, Ca, Mn and Cu in S fertilized compared to non-S fertilized sorghum. Sulphur fertilization decreased (P < 0.05) concentration of hydrocyanic acid (HCN) in the upper three leaves. A greenhouse experiment was conducted with the Lucy soil and 'Pioneer 947' sorghum to further investigate effects of fertilization (0, 70, and 140 kg S ha ⁻¹) as ammonium sulphate in a completely randomized design with five replications. Sulphur application decreased soil pH, and extractable soil K linearly (P < 0.01), and increased extractable soil S linearly (P < 0.01).
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    Nutrient composition of ensiled alfalfa and corn forages grown in Virginia
    Ahmad, Muhammad Rashid (Virginia Tech, 1991-05-24)
    Corn (Zea mays) and alfalfa (Medicago sativa) silages are used extensively in Virginia. A survey was conducted to determine chemical composition of these two forage silages grown in five geographical regions of Virginia; Eastern Virginia (EV), Northern Piedmont (NP), Southern Piedmont (SP), Shenandoah Valley (SV), and South-Western Virginia (SWV). A total of 889 samples of corn silage, 106 of ammoniated corn silage and 247 of alfalfa silage collected during 1988 and 1989 from 76 counties, were analyzed for fiber, N, and macro- and micro-nutrients. Chemical composition of the silages was correlated with S applied in fertilizer or manure. Data were compared with critical levels of mineral requirements of various classes of livestock. Alfalfa silage was higher (P < 0.05) in crude protein (CP), P, K, Ca, Mg, S, Mn, and Fe than com silage. Ammoniated corn silage was higher (P < 0.01) in CP and NS ratio, and lower in P, S (P < 0.01) and K (P < 0.05) concentrations than non-ammoniated corn silage. For lactating dairy cows, 86 and 95% of corn silage and ammoniated corn silage, respectively, grown throughout the State were deficient in P. Information supplied by farmers suggested that manure application increased P concentration of these forages. Over 90% of all corn silage would not have met the Ca requirements of dairy cows, however, 97% of the alfalfa silage was excessive in Ca concentration for dairy cows and could have served as a Ca supplement to the diet. Nitrogen:S ratio indicated S deficiency (N:S ratio > 12) in 34, 89 and 41% of samples of corn silage, ammoniated corn silage and alfalfa silage for dairy cattle and in 85, 96 and 91% of the respective silages for sheep (N:S ratio > 10). Based on S concentrations, 96% of corn silage and ammoniated corn silage grown throughout Virginia were S deficient for dairy cows while 72% of corn silage and 86% of ammoniated corn silage were deficient in S for sheep. Sulphur concentrations in silages did not indicate S deficiencies for plant growth. Over 60% of corn and alfalfa silages would not have met nutritional requirements for Zn and Cu in lactating dairy cows but requirements for Mg and Mn would have been supplied by more than half of the silages produced in Virginia. Regional/ geographical variations in almost all the nutrients were observed for both forages. Generally, corn silage grown in EV was lower in CP, TDN, Mg, and Mn and was higher in ADF compared to silage grown in the rest of the State. Lower CP, Ca, and S were observed in alfalfa silage grown in EV compared to the mean of other regions. Generally, higher N:S ratio in corn and alfalfa silages and lower P were found in alfalfa silage grown in Western Highlands compared to Piedmont region. Also CP and Ca were lower in corn silage grown in SWV compared to SV while Mg was lower in either silage grown in SV compared to SWV region. In general, concentrations of P, Ca, S, Zn, and Cu in corn silage and ammoniated corn silage were widely deficient ( > 70% samples deficient) for dairy cattle, and deficient in S for sheep. Magnesium deficiencies were less frequent. In alfalfa silage concentrations of Zn, and Cu were low for dairy cows. Nitrogen:S ratios indicated S deficiency for livestock, particularly in sheep and lactating dairy cows.