Differential responses of growth and nitrogen uptake to organic nitrogen in four gramineous crops

Abstract

The capability to utilize different forms of nitrogen (N) by sorghum (Sorghum bicolor), rice (Oryza sativa), maize (Zea mays), and pearl millet (Pennisetum glaucum) was determined in pot experiments. Seedlings were grown for 21 d without N, or with 500 mg N kg(-1) soil applied as ammonium nitrate, rice bran or a mixture of rice bran and straw. No treatment-dependent changes of root length, surface area, and fractal dimension were observed. Shoot growth and N uptake in maize and pearl millet correlated with the inorganic N (ammonium and nitrate) concentration in the soil, suggesting that these species depend upon inorganic N uptake. On the other hand, shoot growth and N uptake patterns in sorghum and rice indicated that these two species could compensate low inorganic N levels in the organic material treatments by taking up organic N (proteins). Analysis of N uptake rates in solution culture experiments confirmed that sorghum and rice roots have higher capabilities to absorb protein N than maize and pearl millet.

Significance of Plant-induced Solubilization of Soil Nitrogen: A Case of Komatsuna Plants Grown in Fertilized Soils

“…The high contribution of plant-induced solubilization to N uptake has also been reported at least for white lupin (Watanabe et al, 2006), sorghum (Okamoto et al, 2004) and F. vivipara (a grass growing in sub-arctic montane in north Sweden) (Jonasson et al, 2006). In these studies, both planted and unplanted soils were examined, by which the contribution of solubilization by the plant could be estimated in a way similar to ours.…”

“…Bars with * and + indicate significant differences between the planted and unplanted treatments at the level of P<0.05 and P<0.1, respectively (t-test). Okada, 2004;Watanabe et al, 2006). The concentration of inorganic N in soil planted with F. vivipara became higher than that in the unplanted soil in half of the treatments (Jonasson et al, 2006).…”

“…In particular, information is still lacking on the contribution of such solubilization to the total amount of N taken up by plants. The high contribution has been reported only in a few plant species such as sorghum (Sorghum bicolor L.) (Okamoto and Okada, 2004), white lupin (Lupinus albus L.) (Watanabe et al, 2006) and a viviparous grass in the sub-arctic montane (Festuca vivipara L.) (Jonasson et al, 2006). Further confi rmation of these results is required to estimate the importance of plantinduced solubilization of soil N as one of the N-driving processes in the soil-plant systems (Fig.…”

Inter-specific variability in protein use by two vegetable crop species

“…However, the level of proteolytic activity in the culture medium of different plant species varied significantly (Godlewski and Adamczyk, 2007). Also the uptake of amino acids -the product of proteolysis process -differs between various plant species (weigelt et al, 2003okamoto and Okada, 2004;Reeve et al, 2009).…”

Absorção e assimilação de uréia pela bromélia epífita com tanque Vriesea gigantea

“…Moreover, Näsholm et al [53] showed the ability of five important crop species (Phleum pretense, Ranunculus acris, Trifolium hybridum, Trifolium pretense and Triticum aestivum) to take up the amino acid glycine [53,54]. Even proteins can be used by some plant species (Sorghum bicolor and Oryza sativa), as demonstrated by Okamoto and Okada [55]. They found that these two species possess high capabilities for taking up protein, which could be important when they are cultivated in low inorganic N concentrations.…”