scholarly journals Weeding Frequencies Decreased Rice–Weed Competition and Increased Rice N Uptake in Organic Paddy Field

Agronomy ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1904
Author(s):  
Margi Asih Maimunah ◽  
Valensi Kautsar ◽  
Putu Oki Bimantara ◽  
Samuel Munyaka Kimani ◽  
Ren Torita ◽  
...  
Keyword(s):  
Paddy Field ◽  
Rice Field ◽  
N Uptake ◽  
Tiller Number ◽  
Weed Competition ◽  
Weed Biomass ◽  
Organic Rice ◽  
Rice Growth ◽  
N Concentration ◽  
Weed Diversity

Different weeding frequencies (WFs)―0WF, 2WF, 4WF, 6WF, and 8WF―were adopted in an organic rice field to investigate their influence on weed types, rice and weed biomass, rice tiller and weed number, N concentration, and N uptake. The study field was located in Tsuruoka, Yamagata, Japan. Rice (cv. Sasanishiki) was planted from May to September 2019, and all weeding events were carried out until 49 days after transplantation (DAT) using a rotary weeder. Rice and weed samples were collected at 60, 88, and 110 DAT. Echinochloa crus-galli (E. crus-galli), Schoenoplectus juncoides, and Monochoria vaginalis (Burm. f.) were the most commonly found weeds. High weed diversity was observed at both 6WF and 8WF, E. crus-galli was the dominant weed at 0WF. Compared to 0WF, 2WF displayed a significantly decreased weed biomass. However, at 8WF, the weed biomass was reduced by 79.0%, the rice biomass was increased by 277%, and the rice tiller number was almost three times higher than that at 0WF and 110 DAT. Compared to 0WF, a significantly increased rice N uptake was observed at 4WF, and rice N uptakes achieved at 6WF and 8WF were two and four times higher than those at 0WF, respectively. Higher weeding frequencies provide notable benefits in suppressing weeds and supporting rice growth, especially in N uptake competition with weeds.

Effect of film-mulched treatment on weed diversity in rice field

2009 ◽  
Vol 17 (2) ◽  
pp. 195 ◽  
Author(s):  
Zhao Xin ◽  
Lin Chaowen ◽  
Xu Mingqiao ◽  
Huang Jingjing ◽  
Chen Yibing ◽  
...  
Keyword(s):  
Rice Field ◽  
Weed Diversity

scholarly journals Ethephon Reduces Maize Nitrogen Uptake but Improves Nitrogen Utilization in Zea mays L.

2022 ◽  
Vol 12 ◽  
Author(s):  
Yushi Zhang ◽  
Yubin Wang ◽  
Churong Liu ◽  
Delian Ye ◽  
Danyang Ren ◽  
...  
Keyword(s):  
Grain Yield ◽  
Plant Density ◽  
N Uptake ◽  
Utilization Efficiency ◽  
N Application ◽  
Total N ◽  
N Concentration ◽  
High Plant Density ◽  
Ethephon Treatment ◽  
N Use

Increasing use of plant density or/and nitrogen (N) application has been introduced to maize production in the past few decades. However, excessive planting density or/and use of fertilizer may cause reduced N use efficiency (NUE) and increased lodging risks. Ethephon application improves maize lodging resistance and has been an essential measure in maize intensive production systems associated with high plant density and N input in China. Limited information is available about the effect of ethephon on maize N use and the response to plant density under different N rates in the field. A three-year field study was conducted with two ethephon applications (0 and 90 g ha−1), four N application rates (0, 75, 150, and 225 kg N ha−1), and two plant densities (6.75 plants m−2 and 7.5 plants m−2) to evaluate the effects of ethephon on maize NUE indices (N agronomic efficiency, NAE; N recovery efficiency, NRE; N uptake efficiency, NUpE; N utilization efficiency, NUtE; partial factor productivity of N, PFPN), biomass, N concentration, grain yield and N uptake, and translocation properties. The results suggest that the application of ethephon decreased the grain yield by 1.83–5.74% due to the decrease of grain numbers and grain weight during the three experimental seasons. Meanwhile, lower biomass, NO3- and NH4+ fluxes in xylem bleeding sap, and total N uptake were observed under ethephon treatments. These resulted in lower NAE and NUpE under the ethephon treatment at a corresponding N application rate and plant density. The ethephon treatment had no significant effects on the N concentration in grains, and it decreased the N concentration in stover at the harvesting stage, while increasing the plant N concentration at the silking stage. Consequently, post-silking N remobilization was significantly increased by 14.10–32.64% under the ethephon treatment during the experimental periods. Meanwhile, NUtE significantly increased by ethephon.

Topsoil replacement depth and organic amendment effects on plant nutrient uptake from reclaimed natural gas wellsites

2006 ◽  
Vol 86 (5) ◽  
pp. 859-869 ◽  
Author(s):  
Francis Zvomuya ◽  
Francis J Larney ◽  
Olalekan O Akinremi ◽  
Reynald L Lemke ◽  
Vasile E Klaassen
Keyword(s):  
Nutrient Uptake ◽  
Organic Amendment ◽  
N Uptake ◽  
C:N Ratio ◽  
Wheat Crop ◽  
Plant Nutrient ◽  
Low Carbon ◽  
South Central ◽  
N Concentration ◽  
Cattle Feedlot

Sustained plant nutrient a vailability on reclaimed wellsites is critical to the successful restoration of crop productivity. This study evaluated topsoil replacement depth (TRD) (0, 50, 100, and 150% of mandatory TRD) and organic amendment [beef cattle feedlot manure, compost derived from straw-bedded cattle feedlot manure, wheat (Triticum aestivumL.) straw, alfalfa (Medicago sativaL.) hay, and unamended control] effects on nutrient uptake by a wheat crop at three abandoned gas wellsites in south-central Alberta. Grain N uptake increased by 0.055 kg ha-1 for each percent increase in TRD, reflecting the corresponding linear increase in grain N concentration. Low carbon to nitrogen (C:N) ratio amendments, particularly compost and alfalfa, were the most effective for improving grain N concentration and uptake. Conversely, N concentration and uptake were lowest for the high C:N (53:1) wheat straw amendment. Reclamation programs should, therefore, consider incorporation of the low C:N alfalfa or compost in order to safeguard against N deficiency in the first 1–2 yr following reclamation. Our results also show that high P amendments, such as manure and compost, are better choices for improving P uptake by spring wheat. These results emphasize the importance of topsoil replacement and amendment quality (C:N ratio and P concentration) in ensuring adequate N and P supply in the 1–2 yr following reclamation. Based on this, compost appears to be the best single amendment for ensuring enhanced uptake of both N and P on reclaimed wellsites in the short term. Key words: Topsoil replacement; organic amendments; reclamation; nitrogen; phosphorus

Effects of biochar amendment on rice growth and nitrogen retention in a waterlogged paddy field

2014 ◽  
Vol 15 (1) ◽  
pp. 153-162 ◽  
Author(s):  
Da Dong ◽  
Qibo Feng ◽  
Kim McGrouther ◽  
Min Yang ◽  
Hailong Wang ◽  
...  
Keyword(s):  
Paddy Field ◽  
Nitrogen Retention ◽  
Rice Growth ◽  
Biochar Amendment

scholarly journals Dry Bean Morpho-Physiological Responses to Gradual Weed Biomass Accumulation

2013 ◽  
Vol 5 (1) ◽  
pp. 74-78
Author(s):  
Hossein GHAMARI ◽  
Goudarz AHMADVAND
Keyword(s):  
Biomass Accumulation ◽  
Physiological Traits ◽  
Weed Competition ◽  
Dry Matter Accumulation ◽  
Dry Bean ◽  
Weed Biomass ◽  
Weed Interference ◽  
Free Treatment ◽  
Crop Cycle ◽  
Number Of Branches

Field study was carried out in 2011 in west of Iran to assess responses of dry bean (Phaseolus vulgaris L.) morpho-physiological traits to gradual weed biomass accumulation. The treatments consisted of two different periods of weed interference, which weeds either infested the plots or removed for an increasing duration of time (0, 10, 20, 30, 40, 50 days) after crop emergence. Relative dominance and relative importance of weed species fluctuated over the crop cycle. As the duration of weed interference was increased, a declining trend of crop growth rate (CGR) was observed. When weeds were allowed to compete with crop throughout the crop cycle, maximum value of CGR was decreased from 25.57 g m-2 days in full season weed free treatment to 16.78 g m-2 days in full season weed infested treatment. Effect of treatments on leaf area index (LAI) was significant. Weed removal increased LAI but it could not significantly affect this trait, at the early of growing season. Weed interference caused a significant reduction on number of branches. The minimum number of branches was registered in full season weed infested treatment (2.58 branches per plant), while the maximum one was observed in the full season weed free treatment (4.25 branches per plant). Weed competition severely reduced crop yield. At 10 and 20 days after crop emergence, weed infestation could not significantly affect the yield. A negative relationship between weeds’ dry matter accumulation and LAI as well as number of branches was observed which signify the vulnerability of these morpho-physiological traits to weed competition.

Grain nitrogen concentration differences among three sorghum hybrids with similar grain yield

1999 ◽  
Vol 50 (2) ◽  
pp. 137 ◽  
Author(s):  
A. Kamoshita ◽  
M. Cooper ◽  
R. C. Muchow ◽  
S. Fukai
Keyword(s):  
Grain Yield ◽  
Nitrogen Concentration ◽  
N Uptake ◽  
Grain Filling ◽  
Yield Potential ◽  
Yield Reduction ◽  
N Availability ◽  
N Accumulation ◽  
N Concentration ◽  
Grain Nitrogen

The differences in grain nitrogen (N) concentration among 3 sorghum (Sorghum bicolor (L.) Moench) hybrids with similar grain yield were examined under N-limiting conditions in relation to the availability of assimilate and N to grain. Several manipulation treatments [N fertiliser application, lower leaves shading, thinning (reduced plant population), whole canopy shading, canopy opening, spikelet removal] were imposed to alter the relative N and assimilate availability to grain under full irrigation supply. Grain N concentration increased by either increased grain N availability or yield reduction while maintaining N uptake. Grain N concentration, however, did not decrease in the treatments where relative abundance of N compared with assimilate was intended to be reduced. The minimum levels of grain N concentration differed from 0.95% (ATx623/RTx430) to 1.14% (DK55plus) in these treatments. Regardless of the extent of variation in assimilate and N supply to grain, the ranking of hybrids on grain N concentration was consistent across the manipulation treatments. For the 3 hybrids examined, higher grain N concentration was associated with higher N uptake during grain filling and, to a lesser extent, with higher N mobilisation. Hybrids with larger grain N accumulation had a larger number of grains. There was no tradeoff between grain N concentration and yield, suggesting that grain protein concentration can be improved without sacrificing yield potential.

Mass loss and nitrogen dynamics during the decomposition of a 15N-labeled N2-fixing epiphytic lichen, Lobaria oregana

2003 ◽  
Vol 81 (7) ◽  
pp. 698-705 ◽  
Author(s):  
Scott M Holub ◽  
Kate Lajtha
Keyword(s):  
Mass Loss ◽  
N Mineralization ◽  
Decay Constant ◽  
N Uptake ◽  
Nitrogen Dynamics ◽  
Net N Mineralization ◽  
Epiphytic Lichen ◽  
Surrounding Environment ◽  
N Concentration ◽  
Lobaria Oregana

We studied mass loss and nitrogen dynamics during fall and spring initiated decomposition of an N2-fixing epiphytic lichen, Lobaria oregana (Tuck.) Müll. Arg., using 15N. We developed a method of labeling lichens with 15N for use in a decomposition study that involved spraying lichen material with a nutrient solution containing 15N-enriched ammonium. Through the first 180 days of sampling, lichens placed in the field during the spring had a smaller decay constant (k = 1.24 year–1) than the lichens placed in the field during the fall (k = 3.1 year–1). However, both spring and fall lichen samples were decomposed beyond recognition after 1 year. Patterns in exogenous N uptake and N concentration did not differ by season. Both spring and fall lichens took up N from the surrounding environment during decay while simultaneously losing N to the environment. The N concentration in both sets of lichen additions increased during decay to a peak of around 2.8% N, equal to a C to N ratio of about 16, and then began to decrease. This indicates that early in decay, net N immobilization occurred in the remaining lichen, but this was followed by net N mineralization in later stages of decay.Key words: decomposition, nitrogen, Lobaria oregana, lichen, mineralization, immobilization.

scholarly journals The Study and Development of Endophytic Bacteria for Enhancing Organic Rice Growth

2012 ◽  
Vol 32 ◽  
pp. 172-176 ◽  
Author(s):  
A. Duangpaeng ◽  
P. Phetcharat ◽  
S. Chanthapho ◽  
N. Boonkantong ◽  
N. Okuda
Keyword(s):  
Endophytic Bacteria ◽  
Organic Rice ◽  
Rice Growth
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