Effect of nitrogen fertilizer application on growth, biomass production and N‐uptake of torpedograss (Panicum repens L.)

Abstract

A glasshouse study was conducted to evaluate the effects of different rates (0, 50, 100, 200 and 400 kg ha -1 ) of nitrogen (N) fertilizer application on the growth, biomass production and Nuptake efficiency of torpedograss. The growth responses of torpedograss to the N application were significant throughout the observation periods. Torpedograss grown for 60 days obtained the highest total biomass of 23.0 g plant -1 with an application of 200 kg ha -1 N, followed by 20.4 g plant -1 with an application of 100 kg ha -1 N; when it was grown for 90 days a significantly higher biomass of 102.3-106.0 g plant -1 was obtained with the 200-400 kg ha -1 N than the biomass (68.0 g plant -1 ) obtained with the fertilizer applied at a lower rate. When the torpedograss was grown for 130 days the highest biomass was 230.0 g plant -1 with the 400 kg ha -1 N application, followed by a biomass of 150.0 g plant -1 with the 200 kg ha -1 N application, but the above-ground shoot in all treatments was over mature for animal food. The ratio of the above-ground shoot to the underground part increased with the increase in N application up to 400 kg ha -1 during the 90 days after planting (DAP), but the above-ground shoot biomass was the same with the 200 and 400 kg ha -1 N. The agronomic efficiency of the N application decreased to 5-38 with the increase in N application to 400 kg ha -1 , which was less than half the agronomic efficiency with the 200 kg ha -1 N. The agronomic efficiency of N was very low (5-22) during the 60 DAP, which indicated that the N application would not be economically viable in this period for torpedograss as a pasture, and short-duration plants could be cultivated in torpedograss-infested fields to minimize weed-crop competition. The nitrogen concentration (%) in the torpedograss increased with the increase in N application, but N-uptake efficiency was the opposite and the value was very low with the 400 kg ha -1 N. The above results lead us to conclude that the N application rate of 200 kg ha -1 is the most effective for torpedograss growth.

Effects of soil types and fertilizers on growth, yield, and quality of edibleAmaranthus tricolor linesin Okinawa, Japan

“…The growth parameters and yield of BC amaranth line increased almost similarly with all fertilizer levels (Table 4), but agronomic efficiency tented to decrease with the 40 and 50 g m −2 , indicating that the fertilizer rate of 20-30 g m −2 is better for BC cultivation in gray soil. Similar trend in agronomic efficiency of fertilizer was found in Panicum repens, Sorghum almum, and Allium sativum (Hossain et al, 2004;Nori et al, 2012;Olanite et al, 2010).…”

“…The treatment of HN resulted in lower shoot dry weight than lN, indicating that excessive level of N fertilizer without P and K was not balanced for plant to uptake necessary nutrients or proper photosynthetic function. Similarly, other studies reported that a plant species increases biomass with the increasing N application up to a certain level, thereafter decreases (Hossain et al, 2004;Nori et al, 2012;Olanite et al, 2010).…”

“…Different plant species respond differently to fertilizer rates and combination and a plant species requires balanced fertilizers to maximize growth, yield, and quality (Akamine et al, 2007;Chowdhury et al, 2008;Hafsi et al, 2011;Hossain et al, 2004). The major nutrients (N, P, K) individually or in combination maintain growth, yield, and quality of plants (Hafsi et al, 2011;Ivonyi et al, 1997;Mazid, 1993;Nakano & Morita, 2009).…”

Arrowhead (Sagittaria cuneata) as a bioindicator of nitrogen and phosphorus for prairie streams and wetlands

“…Plants in the control trial grew poorly and often remained in submerged form, indicating that they did not have access to sufficient nutrients to reach maturity and thus produce emergent leaves and numerous reproductive propagules. The finding that AG:BG biomass ratios were greater for the sediment-enriched plants compared to both the water-enriched and control trials is consistent with our hypothesis of nutrient insufficiency in the latter two trials, as both terrestrial and aquatic plants allocate resources to belowground production instead of aboveground structures (Neill 1990 ; Hossain et al 2004 ; Ket et al 2011 ) when nutrient availability is limited (Darby and Turner 2008 ).…”

A comparison of crop data measured by two commercial sensors for variable-rate nitrogen application

“…Previous research demonstrated that larger rates of N increased not only the aboveground biomass but also the total Chl content of leaves (Fangmeier et al 1996;Ma et al 2005). Both of these properties reached a maximum at moderate or large rates of N, and some authors have even reported reductions at large N rates (Tóth et al 2002;Hossain et al 2004). In 2006, the relation between NDVI and rate of N applied was unusual for both sensors; it decreased as N supply increased from 30 kg N ha -1 to 180 kg N ha -1 (Table 5).…”