scholarly journals Trace Metal Distribution and Mobility in Soils after Silvicultural Thinning and Burning

2017 ◽  
Vol 9 (5) ◽  
pp. 83
Author(s):  
Ngowari Jaja ◽  
Monday Mbila ◽  
Yong Wang

Silvicultural thinning and burning are common management practices that are widely used to address ecosystem problems such as tree stocking and general forest health. However, high-severity fire has variable effects on soils, resulting in damages which are directly or indirectly reflected on the trace metal chemistry of the soil. This study was conducted to evaluate the trace metal variation at the Bankhead National Forest in Northern Alabama following the silvicultural thinning and burning. The experimental site had treatments consisting of two burning patterns and three levels of thinning as part of an overall treatment of three burning patterns and three levels of thinning applied to nine treatment plots to fit a completely randomized block design experiment. Four treatments sites were used for this study and samples were collected from soil profile pits excavated at representative plots within each treatment. The samples were analyzed for trace metals-As, Cu, Ni, Zn and Pb-using Perkin Elmer 2100 ICP-OES. Post treatment samples indicated that the trace metal concentrations generally decreased with soil depth. Copper, Ni, and Zn at the Pre-burn site gradually increased with depth to a maximum concentration at about 50 cm below the soil surface. Arsenic in the surface horizons increased by 156% in the burn-only sites, 54% in the thin-only treatment, 30% for the burn and thin treatments. Such differences were unlikely due to differences in the geochemistry of the parent material, but likely due to anthropogenic activities and possibly the forest management practices in question.

2017 ◽  
Vol 47 (3) ◽  
pp. 185-194 ◽  
Author(s):  
Adriano Stephan NASCENTE ◽  
Ruby KROMOCARDI

ABSTRACT The upland rice farmers in Suriname use local varieties and low level technologies in the field. As a result, the upland rice grain yield is low, at about 1 000 kg ha-1. Our objective was to evaluate the use of upland rice cultivars from Suriname and Brazil, and the effect of nitrogen, N, phosphorus, P, and potassium, K, fertilizers on cultivation variables. We undertook four field trials in the Victoria Area, in the Brokopondo District, using a randomized block design each with four replications. The most productive rice varieties were BRS Esmeralda (grain yield 2 903 kg ha-1) and BRS Sertaneja (2 802 kg ha-1). The highest grain yield of 2 620 kg ha-1 was achieved with a top dressing application of 76.41 kg N ha-1 20 days after sowing. For P, the highest grain yield of 3 085 kg ha-1 was achieved with application of 98.06 kg ha-1 P2O5 applied at sowing. An application rate of 31.45 kg ha-1 of K2O at sowing achieved the highest grain yield of 2 952 kg ha-1. Together, these application rates of N, P and K resulted in rice grain yield of about 3 000 kg ha-1, which is three times greater than the national average for upland rice. We demonstrate that the use of improved rice varieties matched to the local conditions, and application of appropriate fertilizers, are management practices that can result in significant increases in rice grain yield in Suriname.


2012 ◽  
Vol 40 (1) ◽  
pp. 212 ◽  
Author(s):  
Ines HAN DOVEDAN ◽  
Sanja MORIC ◽  
Zoran SINDRAK ◽  
Ivana CEROVSKI ◽  
Ivan MUSTAC ◽  
...  

Iris adriatica is indigenous to Mediterranean part of Croatia. It is an attractive plant and has opportunities for introduction into horticulture and the ornamental plant market. Research was conducted in the experimental garden of the Faculty of Agriculture, University of Zagreb, to assess the possibility of growing this species as a pot plant. Research included 360 potted plants placed as randomized block design experiment. The goal of this research was to determine influence of chosen substrates and fertilizers, as well as to explore growth and development dynamic of the species cultivated outdoors from June till August 2010. The following characteristics were measured: plants height, number of leaves, and number of rosettes. Biometric analysis showed that the development of Iris adriatica was significantly influenced only by substrate, while fertilization and interaction of substrate and fertilization showed no significant impact on examined plants characteristics.


2018 ◽  
Vol 45 (3) ◽  
pp. 249
Author(s):  
Solikin ,

Dioscorea is potentially used as staple food to support food security. The research was aimed to determine the effect of stake length and time of  stem twining  on  the growth of Dioscorea sansibarensis Pax. The experiment was conducted  in  Purwodadi Botanic Garden from December 2014 until May 2015 using split plot randomized block design consisted of two factors, i.e. the stake length and time of stem twining. The stake length was the main plot consisted of 150 cm, 100 cm and 50 cm above soil surface and without stake (control). The time of stem twining as subplots, i.e. stem twined early, twined at the time of 4 leaves stage, and twined at 8 leaves stage. Each combination of the treatments was replicated three times. The results showed that there was significant effect on the stake length  and the time of stem twining treatments on the plant growth and yield. The stake  length of 150 cm treatment produced the highest fresh tuber and total plant dry weight, i.e., 257.24 g and 132.77 g per plant, respectively. On the contrary, the plant without stake produced the lowest fresh tuber and  total dry weight of plant, i.e., 112.10 g and 48.65 g per plant, respectively.<br /><br />Keywords: biomass,leaf area, photosyntesis, tuber weight


2012 ◽  
Vol 36 (5) ◽  
pp. 951-960
Author(s):  
Paulo Sérgio Lima e Silva ◽  
Alexandre Emanuel Régis Holanda ◽  
Haroldo Nogueira de Paiva ◽  
Fábio Henrique Tavares de Oliveira ◽  
Odaci Fernandes de Oliveira

Planting densities influence several aspects of forest formation, including management practices, timber yield, quality, and extraction, and consequently its production costs. The objective of this study was to evaluate Mimosa caesalpiinifolia and Gliricidia sepium growth as a function of planting density (400, 600, 800, 1000, and 1200 plants ha-1) and plant age. The species were evaluated every 90 days for plant height (PH), crown diameter (CD) and root collar diameter (RCD) (10 cm above the ground), with the first evaluation performed at 90 days and the last at 720 days. When plants were one year of age and beyond, evaluations were conducted also for stem diameter at breast height (DBH) (1.30 m above the ground). A randomized block design with split-plots and three replicates was adopted. Species were assigned to plots, planting densities were assigned to subplots, and evaluation ages were assigned to subsubplots. The four traits in both species had their values decreased as planting density increased, but continually increased as plant age increased. For PH and RCD there was an alternation between species superiority, with gliricidia being superior to sabiá at some ages, while the opposite occurred at other ages. As to CD the species only differed in the last measurement, gliricidia being superior. With regard to DBH, gliricidia was superior starting from the second measurement. There was an effect of the species × ages interaction for the four traits and also an effect of the densities × ages interaction for CD and DBH.


1970 ◽  
pp. 33-36
Author(s):  
A. ANBURANI

The present investigation was carried out to study the effect of off season soil management practices on yield and quality of turmeric (Curcuma longa L.) cultivars. The experiment was laid out in a Factorial Randomized Block Design with ten treatments in three replications consisted of five off-season land management treatments viz., fallow (S1), summer ploughing 2 times (S2), summer ploughing 1 time (S3), solarization with transparent polyethylene film of 0.05 mm thick for 40 days (S4) and black polyethylene film for 40 days (S5). It was tested with two popular cultivars viz., Curcuma longa -1 CL-1 (V1) and Curcuma longa-2 CL-2 (V2), collected from Erode and Chidambaram. Various yield components were recorded at the time of harvest and were analysed. The yield attributing characters viz., number, length, girth and weight of mother, primary and secondary rhizomes were recorded. The treatment where solarization with transparent polyethylene film of 0.05 mm thick was tested recorded the highest yield and yield attributing characters when compared to other treatments. The same treatment also exhibited the highest fresh rhizome yield per plant, curing percentage and cured rhizome yield. The quality parameters like curcumin, oleoresin and essential oil content were also showed superior performance in the treatment where solarization with transparent polyethylene film of 0.05 mm thick was applied.


Author(s):  
Claudivan F. de Lacerda ◽  
Jorge F. da S. Ferreira ◽  
Donald L. Suarez ◽  
Emanuel D. Freitas ◽  
Xuan Liu ◽  
...  

ABSTRACT The aim of this study was to evaluate the accumulation of salts in the soil from irrigation water and of N and K from fertilization. The experiment was conducted in PVC columns (20 cm in diameter and 100 cm in height), filled with non-saline soil, and cultivated with maize. A completely randomized block design in a 4 x 4 factorial was used, with four levels of salinity (0.5, 2.5, 5.0 and 7.5 dS m-1), four N rates, and five replicates. Nitrogen was applied as urea and potassium nitrate at the following rates: N1: N recommendation for maize (2.6 g column-1); N2: 0.3 times (0.78 g column-1) the recommended N1 dose; N3 and N4 with N based on N1 and N2 doses, respectively, reduced proportionally based on the evapotranspiration reduction caused by salinity. After 74 days from sowing, root and soil samples were collected at different soil depths. The electrical conductivity of the saturated extract (ECe) and the concentration of ions (Ca2+, Na+, and Cl-) increased as a function of salinity and soil depth. The opposite was observed for the root system. The increase in salinity also resulted in K+ and NO3- accumulation in the soil column, mainly in treatments with higher N rates (N1 and N3). At the end of the experiment, 88% of the NO3- applied at the highest salinity treatment (7.5 dS m-1) and the highest N rate (N1) was below 20 cm soil depth, evidencing a N loss process caused by leaching.


Author(s):  
B. Sandhya Rani ◽  
V. Chandrika ◽  
G. Prabhakara Reddy ◽  
P. Sudhakar ◽  
K.V. Nagamadhuri ◽  
...  

Background: Maize followed by summer pulses is the emerging cropping system in many places in India. Herbicides are the efficient tools for checking weed infestation and their usage is increasing throughout the globe due to increased labour cost and quick weed control. Some herbicides do not degrade quickly and may remain in the soil for weeks, months or years after application and may inhibit the growth of succeeding crops. Methods: Field experiment was conducted in a randomized block design (RBD) during rabi and summer seasons of 2017-18 and 2018-19 to know the residual effect of different herbicides applied in maize on succeeding greengram. Result: The present study revealed that lower density and dry weight of total weeds and higher yield attributes and yield was recorded with the practice of adopting two hand weedings at 15 and 30 DAS, which was however, at par with atrazine 1.0 kg ha-1 as PE fb one HW at 30 DAS, atrazine 1.0 kg ha-1 as PE fb topramezone 30 g ha-1 as PoE and atrazine 1.0 kg ha-1 as PE fb tembotrione 120 g ha-1 as PoE, without any significant disparity among them. Herbicides applied in maize did not alter statistically the enzyme activity and microbial count in the soil at harvest of succeeding greeengram. 


2016 ◽  
Vol 29 (2) ◽  
pp. 338-347 ◽  
Author(s):  
VANESSA ZIRONDI LONGHINI ◽  
WÉSLEY CARLOS ROSSINI DE SOUZA ◽  
MARCELO ANDREOTTI ◽  
NATALIA DE ÁVILA SOARES ◽  
NÍDIA RAQUEL COSTA

ABSTRACT: Corn is a nitrogen-intensive crop, and the use of management practices such as inoculation of the seed with diazotrophic bacteria, which can maximize crop productivity and reduce the need of nitrogen fertilizers, may result in lower production costs. The present study aimed to evaluate the effect of inoculation of corn seed with Azospirillum brasilense and controlled addition of nitrogen to topdressing on the nutrition, production components, and productivity of crop grain. The experimental design was a randomized block design, with four replications in a 2 × 5 factorial scheme. The treatments consisted of inoculation or not of corn seed with A. brasilense (at 100 mL per 25 kg of seed) and five nitrogen (N) levels in topdressing (0, 30, 60, 90, and 120 kg N ha-1 from urea [45% N]) were applied when the corn was in the phenological growth stage V6. Foliar macronutrients, foliar chlorophyll index (FCI), production components, and yield of corn grain were valuated. Inoculation of corn seeds with A. brasilense increased plant height and grain yield. Fertilization in topdressing, with N levels up to 120 kg ha-1, linearly increased the foliar nutrients and productivity of corn cultivated in the spring/summer in the low-altitude Cerrado region of Brazil.


2019 ◽  
pp. 1236-1243
Author(s):  
Emmerson Rodrigues de Moraes ◽  
José Geraldo Mageste ◽  
Joicy Vitória Miranda Peixoto ◽  
Luis Augusto da Silva Domingues ◽  
Regina Maria Quintão Lana ◽  
...  

In sugarcane expansion areas where soil fertility restrictions regularly occur, soil preparing ameliorates soil physical and chemical properties to improve conditions for sugarcane crop development. Therefore, the aim of this study was to evaluate soil chemical attributes under different soil preparation methods for sugarcane cultivation at the first and second year of expansion area in the Cerrado biome. The experiment was conducted in an area previously used as pasture land for more than 10 years with Brachiaria decumbens without any soil correction. CTC-2 sugarcane variety was planted. The experiment was set up as a randomized block design with six treatments and four replications. The treatments were: desiccation-liming-plowing-harrowing; liming-plowing-harrowing; liming-harrowing-plowing-harrowing; desiccation-liming-direct planting; desiccation-liming-subsoiling, and harrowing-liming-plowing-harrowing. Soil attributes: organic matter, water pH, H++Al3+, Al3+, m, V, H2PO4-, K+, Ca2+, Mg2+, and S-SO4-2 were evaluated at 0-0.2, 0.2-0.4 and 0.4-0.6 m soil depth. The variables were submitted ANOVA, joint analysis and Tukey’s test (p < 0.05). The treatments including liming followed by harrowing, plowing and harrowing, and harrowing followed by liming, plowing and harrowing, resulted in the largest gains in soil fertility. In the first year of sugarcane cultivation, the no-tillage system proved to be sustainable and appropriate for sugarcane cultivation economically viable.


2015 ◽  
Vol 8 (1) ◽  
pp. 1-11 ◽  
Author(s):  
A.A. Eslami ◽  
S.A. Khodaparast ◽  
S. Mousanejad ◽  
F. Padasht Dehkaei

Summary Sclerotium rolfsii is a soil borne pathogen responsible for root and stem rot on a wide range of crops. This study was conducted to identify the virulence of different S. rolfsii isolates on a susceptible local peanut germplasm and determine the resistance of 20 peanut genotypes to the most virulent isolate and also the relationship between virulence and mycelial compatibility groups (MCGs). Seventy eight isolates of this fungus from 10 host plants and six known MCGs were used in the experiment. The experiment was done in greenhouse conditions (25±5°C) using a complete randomized block design with three replications. Pots containing sterile soil (pH=6.7) were inoculated with barley seeds colonized by each isolate separately before being seeded with the peanut germplasm. Disease severity was assessed by scoring the wilting, yellowing or death of plants, mycelia or sclerotia production on the soil surface or on plant stem, stem area affected (%) and stem lesion length, at the stage of plant maturity. Also, shoot wet weight and plant height were recorded at this stage. According to the results of the pathogenicity tests, all of the isolates were virulent on the susceptible peanut germplasm and the virulence diff ered signifi cantly between the isolates (P≤0.01). There was no relationship between the virulence of the five groups of isolates identified in the present study and the MCGs. The peanut genotype 140, which was better than the others based on seed size, plant height and the canopy size, was also the most resistant one


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