Poor Vertical Root Development May Contribute to Suppression in a Red Pine Plantation

1978 ◽  
Vol 54 (2) ◽  
pp. 99-103 ◽  
Author(s):  
D. C. F. Fayle

Initial stem and root growth of trees that became suppressed within 30 years in a red pine (Pinus resinosa Ait.) plantation were poorer than those that became codominants. Stem and horizontal root extension improved later but then declined. The likelihood of suppression may have been initiated at or before planting. Inadequate development, perhaps through chance, of vertical roots that could tap moisture-holding layers at the 2.8 m depth in the well-drained loamy sand soil contributed to the suppression process.

2019 ◽  
Vol 11 (12) ◽  
pp. 3460 ◽  
Author(s):  
Abdulaziz G. Alghamdi ◽  
Hesham M. Ibrahim

Applications of large amounts of biosolid to agricultural lands have raised the concern over its potential impact on co-transport of metal contaminants. In this study, bulk biosolid was fractioned into six macro- and nano-biosolid fraction sizes. We investigated variations in the physicochemical properties of the different biosolid fraction sizes, and assessed sorption affinity and transport of Pb in a loamy sand soil. Decreasing biosolid fraction size from macro to nano resulted in consistent increases in surface area, surface charge, and a decrease in pore size. Biosolid particles >1000 µm showed similar surface properties that differ from biosolid particles < 1000 µm. Sorption affinity for Pb was larger on nano-biosolid as compared to all macro-biosolid fraction sizes. This is mainly attributed to the larger surface area and zeta potential of nano-biosolid, leading to increased surface reactivity and greater stability. Total amount eluted of Pb was increased in the presence of macro- and nano-biosolid by 21.3% and 45.6%, respectively. Our findings suggest that the application of the >1000 µm biosolid fractions can help to minimize adverse effects of biosolid applied in areas susceptible to potential environmental risk of contamination by heavy metals. Further assessment of potential mobility of nano-biosolid at the field scale is needed before the recommendation of including such approach during land application of biosolid.


1986 ◽  
Vol 29 (2) ◽  
pp. 0389-0392 ◽  
Author(s):  
Jonathan Chaplin ◽  
Mike Lueders ◽  
David Rugg

1992 ◽  
Vol 6 (2) ◽  
pp. 317-321 ◽  
Author(s):  
Rick A. Boydston

Experimental controlled release starch granules (CRSG) containing 5.3% a.i. (w/w) norflurazon or 6% a.i. (w/w) simazine retarded the leaching of both herbicides in loamy sand soil columns when compared to commercial formulations of norflurazon [80% (w/w) dry flowable] or simazine [90% (w/w) water dispersible granule]. Barley bioassays indicated norflurazon and simazine remained in the surface 0 to 2.5 cm of soil when applied as CRSG formulations and moved to a depth of 15 cm when applied as commercial dry formulations and leached with 6 cm of water. CRSG placed on pre-wetted soil columns began to release norflurazon by 7 d at 25 C or 14 d at 15 C, and subsequent leaching moved norflurazon beyond the top 2.5 cm of the soil column.


1965 ◽  
Vol 41 (3) ◽  
pp. 290-294 ◽  
Author(s):  
J. D. Gagnon

The fertilizers, Mg at a rate of 100 lbs/acre and K at 200 lbs/acre, were applied around each of 15 red pine (Pinus resinosa Ait.) to promote increased growth in a 20-year-old plantation which had failed to fulfil growth expectations. Successive measurements of diameter and height showed that the fertilizers stimulated diameter significantly after the second growing season, but height only after the third growing season. Beneficial effect of fertilizer applications on diameter and height persisted, and the differences in diameter and height between treated and untreated trees at the end of the seventh growing season was equivalent to two years' current growth.


2018 ◽  
Vol 10 (9) ◽  
pp. 6 ◽  
Author(s):  
Andre A. Diatta ◽  
Wade E. Thomason ◽  
Ozzie Abaye ◽  
Larry J. Vaughan ◽  
Thomas L. Thompson ◽  
...  

Mungbean [Vigna radiata (L.) Wilczek] is a short-duration and relatively drought-tolerant crop grown predominantly in the tropics. This grain legume can improve soil fertility through biological nitrogen (N) fixation. To assess the effects of Bradyrhizobium (group I) inoculation on yield and yield attributes of mungbean, a greenhouse study was conducted during Fall 2016 with two mungbean cultivars (‘Berken’ and ‘OK2000’), two inoculum treatments (inoculated and uninoculated), and two soil textures (loamy sand and silt loam). Pots were laid out in a completely randomized design and treatment combinations were replicated seven times. The main effects of cultivar and soil texture significantly (P ≤ 0.05) affected mungbean seed weight and plant residue mass. Seed yield (13%), plant residue (22%), and protein content (6%) of OK2000 were significantly higher than Berken cultivar. A 31% seed yield and 40% plant residue increase were recorded on silt loam soil compared to loamy sand soil. Significant increase in plant height (18%) and number of pods per plant (21%) were also recorded when mungbean plants were grown on silt loam compared to loamy sand soil. Bradyrhizobium inoculation significantly increased the number of pods per plant, the number of seeds per plant, and seed yield. [Cultivar × inoculation] and [cultivar × soil texture] interactions had significant (P ≤ 0.05) effects on number of seeds per pods and plant height, respectively. Understanding the agronomic practices and soil physical properties that may limit mungbean production could help in optimizing its establishment and growth in non-traditional growing areas.


1990 ◽  
Vol 4 (4) ◽  
pp. 754-758 ◽  
Author(s):  
W. Carroll Johnson ◽  
Benjamin G. Mullinix

Studies on the efficacy and economic analysis of Texas panicum management systems in corn were conducted in Georgia on a loamy sand soil in 1987, 1988, and 1989. Management systems that included butylate, EPTC, atrazine plus tridiphane, atrazine plus pendimethalin, atrazine plus trifluralin, paraquat, or ametryn acceptably control Texas panicum. Corn yields were not affected significantly by the Texas panicum management systems. Overall net returns calculated for corn production indicated that systems which included postemergence applications of atrazine, pendimethalin, trifluralin, paraquat, ametryn, or cultivation alone gave the highest net returns. Systems which included butylate, EPTC, or tridiphane frequently had significantly lower net returns.


Sign in / Sign up

Export Citation Format

Share Document