Effect of Nitrogen Fertilization on Oxalate Content in Rhodesgrass, Guineagrass and Sudangrass

Abstract

An experiment was conducted to evaluate the effects of nitrogen (N) level on the dry matter (DM) yield, N concentration and oxalate content of some tropical grasses, namely Rhodesgrass (Chloris gayana), Guineagrass (Panicum maximum) and Sudangrass (Sorghum vulgare). Three levels of N as urea were applied (Standard-260, Standard×2-540 and Standard×4-1,060 kg N/ha for Rhodesgrass; Standard-380, Standard×2-770 and Standard×4-1,570 kg N/ha for Guineagrass and Sudangrass) in a completely randomized design and grasses were harvested twice at approximately two-month intervals. Dry matter yield tended to be higher with increased rate of N fertilizer in all species, while further additional N (Standard×2 or Standard×4) did not significantly (p>0.05) further increase DM yield, when compared with the Standard level of N fertilizer application. There was also a trend towards higher N concentration in plants as N fertilization increased in all species and it was increased significantly in Rhodesgrass and Sudangrass (p<0.05 or p<0.01, respectively). Further additional N (Standard×2 or Standard×4) application showed no significant (p>0.05) differences on oxalate content in plant tissue within species, when compared with the Standard level of N. The Rhodesgrass contained 0.11, 0.13 and 0.15% soluble oxalate and 0.23, 0.25 and 0.27% total oxalate with Standard, Standard×2 and Standard×4 level of N application, respectively. The Guineagrass contained 0.54, 0.50 and 0.42% soluble oxalate and 1.60, 1.56 and 1.45% total oxalate with Standard, Standard×2 and Standard×4 level of N application, respectively. The Sudangrass contained 0.06, 0.15 and 0.12% soluble oxalate and 0.22, 0.22 and 0.21% total oxalate with Standard, Standard×2 and Standard×4 level of N application, respectively The results from this study suggest that these grasses do not use further addition of N fertilizer (Standard×2 or Standard×4) to form high content of oxalate salts, when compared with the Standard level of N. In addition, the levels of oxalate present with these grasses are quite low as far as toxicity to animals is concerned.

Interactive Effects of Nitrogen and Potassium Fertilization on Oxalate Content in Napiergrass (Pennisetum purpureum)

“…Soluble oxalate content in the first-cut napiergrass was affected (p<0.01) by the N treatments, but this effect was not consistent in the subsequent cuttings and the average soluble oxalate content of 3 cuttings was not altered (p>0.05) by the N treatments. This is in agreement with the results of Rahman et al (2008a) who observed that N fertilization with urea either had no effect on the accumulation or even reduced the level of soluble oxalate. However, in a nutrient solution study, Rahman (2009) has shown that nitrate treated napiergrass contained significantly higher soluble oxalate content than ammonium treated napiergrass.…”

“…As N fertilizer application was increased from 150 to 300 kg/ha, total annual DM yield was increased significantly (p<0.001), whereas increasing N fertilizer from 300 to 600 kg/ha did not increase (p>0.05) it further. These results are in agreement with Rahman et al (2008a) who observed that DM yield of some tropical grasses had peaked at N application of 300 kg/ha. Total annual DM yield was not significantly (p>0.05) affected by K fertilization.…”

Diversity in growth and expression pattern of PoHKT1 and PoVHA transporter genes under NaCl stress in Portulaca oleracea taxa

“…Further, secondary cell appears sooner and cell wall becomes rigid, as a consequence the turgor pressure efficiency in cell enlargement decreases, This processes may cause the shoot remain small (NASEER, 2001). These findings are parallel to those of JAMIL et al (2006) on vegetables species, RAHMAN et al (2008) on wheat and BYBORDI and TABATABAEI (2009). Previous study by ALAM (2014) indicated that the dry matter production was found to increase in some P. oleracea accessions from lower to higher salinity levels but others were badly affected.…”

Effects of levels of nitrogen fertilizer on oxalate and some mineral contents in napiergrass (Pennisetum purpureum Schumach)

“…Jones and Ford (1972) observed an increased oxalate content in S. sphacelata when N fertilizer was applied as urea from 0 to 200 kg ha −1 . Rahman et al . (2008) reported no increase in oxalate content in Chloris gayana , Panicum maximum and Sorghum vulgare when increasing levels of N fertilizer were applied as urea from 260 to 1570 kg ha −1 .…”