bluuebunny/crossref_metadata_2025_split huggingface dataset:
EVALUATION CENTER PIVOT SYSTEMS USING NEW AND OLD SPRAYS AND PRESSURE REGULATORS
Authors: Klar Antonio Evaldo , Santana Renato De Castro , Duroha Charles 
Published: October 2018

EVALUATION CENTER PIVOT SYSTEMS USING NEW AND OLD SPRAYS AND PRESSURE REGULATORS Antonio Evaldo KlarRenato de Castro SantanaCharles DurohaDepartamento de Engenharia Rural – FCA/UNESP18603-970 – Botucatu/SP Fone: (0xx14)6802-7165; Fax: 6802-7194,klar@fca.unesp.br 1 ABSTRACT The objectives of this study were to appraise the performance characteristics for two center pivot irrigation systems (1 and 2) installed on identical areas with different hydraulic conditions: new and old pressure regulators and sprays and the wear out of the equipments. The experiment was been conducted in the Madeira Farm, Silvânia, GO.The Christiansen Uniformity Coefficient (CUC) was been used for the evaluation of the efficiency of systems. The values gotten for the CUC showed that there was an increase in 24.22% and 9.2% after changing old for the new kits and the water depths were 9.20 and 25.02% lower before changing the kits, for pivots 1 and 2, respectively. KEYWORDS: center pivot irrigation, distribution uniformity, old and new pressure regulators and sprays. KLAR, A.E.,SANTANA, R.C., , DUROHA, C. AVALIAÇÃO DE SISTEMAS DE IRRIGAÇÃO POR PIVÔ CENTRAL USANDO DIFUSORES E REGULADORES DE PRECISÃO USADOS E NOVOS 2 RESUMO Os objetivos deste trabalho foram: 1. avaliar as características de desempenho de dois equipamentos de irrigação por pivô central (pivôs 1 e 2), com áreas idênticas, mas em condições hidráulicas diferentes, com reguladores de pressão e difusores novos e usados; 2. através de comparações, quantificar o desgaste do equipamento em condições de campo.Para a avaliação do desempenho dos sistemas, utilizou-se o coeficiente de uniformidade de Christiansen (CUC). Os ensaios foram realizados na Fazenda da Madeira, no município de Silvânia - GO. Os valores encontrados para os coeficientes de uniformidade demonstraram que após a troca dos kits de difusores e de reguladores de pressão, os CUC’s aumentaram em 24,22 % e 34,76 % e as lâminas aplicadas, com os kits usados, foram inferiores ao kits novos em 9,2 % e 25,06%, nos pivôs 1 e 2 respectivamente. UNITERMOS: irrigação por pivô central, uniformidade de distribuição, reguladores de pressão e difusores novos e usados.
DISTRIBUIÇÃO DA EVAPORAÇÃO EM ESTUFA PLÁSTICA NA PRIMAVERA
Authors: Santos Reginaldo Ferreira , Klar Antonio Evaldo 
Published: October 2018

DISTRIBUIÇÃO DA EVAPORAÇÃO EM ESTUFA PLÁSTICA NA PRIMAVERA Reginaldo Ferreira SantosCentro de Ciências Exatas e Tecnológica da UNIOESTE- CP 711CEP 858114-110, Cascavel, PR - Fone: 0XX45 2203155. E-mail: rfsantos@unioeste.brAntonio Evaldo KlarDepartamento de Engenharia Rural - Faculdade de Ciências Agronômica- UNESP - CEP 18603-970 - Botucatu, SP. CP: 237. E-mail: klar@fca.unesp.br 1 RESUMO O presente trabalho teve como objetivo avaliar a distribuição da evaporação no interior de uma estufa plástica, com uma cultura de pimentão, através da variabilidade espacial e comparar a evaporação dos microevaporímetros com os valores do Tanque classe "A". O experimento foi conduzido no Campus da Universidade Estadual Paulista - FCA/UNESP, no período de primavera, em estufa plástica de polietileno de baixa densidade (PEBD). Na distribuição da evaporação em estufa com orientação norte/sul, verificou-se que as maiores evaporações ocorreram nas extremidades sul e norte tendente ao lado oeste. Já as menores evaporações localizaram-se no centro. No período de primavera, a evaporação média nos microevaporímetros superestimou em 55% a evaporação determinada no Tanque classe "A". UNITERMOS: evaporação, geoestatística, estufa. SANTOS, R.F, KLAR, A.E. EVAPORATION DISTRIBUTION INSIDE A PLASTIC TUNNEL IN THE SPRING SEASON 2 ABSTRACT The main aim of this study was to verify the evaporation distribution inside a plastic tunnel, with pepper crop, oriented to north/south, through spatial variability and to compare Class A Pan evaporation to punctual evaporations of 40 equidistant microevaporimeters placed from 50cm the soil. The study was carried out at the College of Agricultural Sciences/UNESP, Botucatu – SP in the spring season. The highest evaporation occurred next to north and to south sides of the tunnel, with tendency to west. Consequently, the lowest evaporations occurred at the center area. The microevaporimeter evaporations were 55% higher than those obtained from Class A Pan. KEYWORDS: evaporation distribution, microevaporimeter.
EFEITO DA FREQÜÊNCIA DE IRRIGAÇÃO SUBSUPERFICIAL POR GOTEJAMENTO NO DESENVOLVIMENTO DA CANA-DE-AÇÚCAR (Saccharum spp.)
Authors: Dalri Alexandre Barcellos , Cruz Raimundo Leite 
Published: October 2018

EFEITO DA Freqüência dE irrigação subsuperficial por gotejamento no desenvolvimento da cana-de-açúcar (Saccharum spp.)[1] Alexandre Barcellos DalriRaimundo Leite Cruz Depto de Eng. Rural – FCA – UNESP – Campus de BotucatuCP 237 – Fone(14) 6802-7165 – CEP. 18603-970 – Botucatu – SP 1 RESUMO Este trabalho teve como o objetivo, verificar o efeito da freqüência da irrigação subsuperficial por gotejamento no desenvolvimento inicial da cana-de-açúcar. Os tubos gotejadores foram instalados sob a linha da cultura, a uma profundidade de 0,3 m. A cana-de-açúcar foi plantada no dia 03/03/2000 e a partir de 01/04/2000 iniciaram os tratamentos nas parcelas irrigadas. O delineamento experimental foi inteiramente casualizado, com quatro tratamentos, e quatro repetições, definidos por regimes de freqüência da irrigação. O sistema de irrigação era acionado quando a evapotranspiração da cultura atingisse 10 mm, 20 mm, e 30 mm, para os tratamentos 1, 2, e 3 respectivamente. O tratamento 4 foi definido como testemunha (não irrigado). A colheita foi realizada no dia 05/12/2000 e através da avaliação de produção de massa fresca, diâmetro e comprimento do colmo, e produção de massa seca, observou-se que não houve diferença estatística entre os diferentes regimes de freqüência de irrigação. Todavia, quando comparado com a testemunha, as irrigações proporcionaram um aumento médio maior que 45 % na produção de massa fresca e seca final dos colmos. UNITERMOS: irrigação por gotejamento subsuperficial, cana-de-açúcar. DALRI, A.B., CRUZ, R.L. EFFECT OF SUBSURFACE DRIP IRRIGATION FREQUENCY ON GROWTH OF SUGARCANE (Saccharum spp.) 2 ABSTRACT The aim of this study was to verify subsurface drip irrigation effects on sugarcane initial growth. Drip lines were set up under crop rows at 0.3 m deep. Sugarcane was planted on March 3, 2000, and drip irrigation treatments began on April 1, 2000. The experimental design was entirely randomized with four treatments and four replications according to irrigation frequency. Irrigation system was turned on when crop evapotranspiration reached 10, 20 and 30 mm for the treatments 1, 2 and 3, respectively. Treatment 4 was considered the control (without irrigation). Harvest was carried out on December 5, 2000, and based on fresh and dry weight, stem diameter and length evaluation no statistical differences for irrigation frequencies have been observed, although irrigation has increased fresh and dried yield over 45% when compared to the control treatment. KEYWORDS: subsurface drip irrigation, sugarcane.[1] Parte da dissertação do primeiro autor, para obtenção do título de Mestre em Agronomia – Irrigação e Drenagem
Nadir Görülen Elastofibroma Dorsi’de Klinik Deneyimimize Dayanarak Tanı Ve Tedavi Algoritması Oluşturulması.
Authors: Keskin Hakan 
Published: October 2018

AMAÇ: Bu çalışmamızdaki
amacımız Elastofibroma Dorsi tanısı ile opere edilen hastaların verilerini
literatür eşliğinde retrospektif olarak inceleyerek elde edilen klinik
sonuçları sunmaktır. Ayrıca Elastofibroma Dorsi için tanı ve tedavi algoritması
önermektir.

MATERYAL VE METOD:

Bu çalışmada
kliniğimizde Ocak 2010- Ağustos 2017 yılları arasında patoloji raporları ile
elastofibrom tanısı alan 31 hasta (toplamda 39 vaka) geriye dönük olarak
incelendi. Hastaların cinsiyetleri,
yaşları, şikâyetleri, tümörün lokalizasyonu, hastanın dominant ekstremitesi,
ailesel yatkınlık hikâyesi olup olmadığı, tanı için uygulanan işlemler ve
karşılaşılan komplikasyonlar değerlendirildi.

BULGULAR:

Hastaların ortalama
yaşları 60,8±5,5 olarak saptandı. Kadın erkek oranı 26/5’dir. Yirmi beş (%80,6)
hasta semptomatikti. Altı (%19,4)hasta ise başka bir nedenle torakotomi
yapılırken tanı aldı ED tanısı alan 5 erkek hastanın 4 tanesinin aktif şikâyeti
olmadığı tespit edildi.

Sekiz (%25,8) hastanın
kitlesinin bilateral olduğu tespit edildi.
Bilateral kitlesi olanların ailesel yatkınlık oranı istatiksel olarak
anlamlı değildi. (p=0,96)

Yirmidört hastanın sağ
ekremitesinin yedi hastanın sol ekstremitesinin dominant olduğu tespit edildi.
Dominant ekstremite ile tümör lokalizasyonlarının istatiksel testlerinde
anlamlı sonuç elde edilmedi.

Hastaların anamnezinde
birinci derece akrabalarında benzer rahatsızlık tarifleyen sadece 4 hasta
mevcuttu. Bu hastaların verileri ile yapılan istatiksel analiz sonucu anlamlı
bir sonuca ulaşılamadı.

SONUÇ:

Tanı için ayrıntılı
anamnez ve fizik muayeneye ilaveten yapılacak olan radyolojik tetkikler ile ED
tanısı konulması güvenilir şekilde yapılabilir.
Ek girişimsel işlemler sadece ED tanısının konulamadığı hastalara
yapılmalıdır. Tedavi için semptomatik hastalarda tümörün total olarak
çıkartılması yeterlidir. Asemptomatik hastalarda cerrahi yapmak, düşükte olsa
var olan akut ve kronik komplikasyon riski nedeniyle gereksizdir.
İZNİK ROMA TİYATROSU BİZANS TOPLUMUNDA DİŞ SAĞLIĞI
Authors: EKİN MERİÇ Aygün , KÖSE Ruken Zeynep 
Published: October 2018

İznik Roma
Tiyatrosunda 2012-2015 yılları arasında
yapılan kazı çalışmalarında Geç Bizans”
dönemine ait 30 bireyin diş kalıntıları üzerine çalışıldı. Geçmiş
toplulukların kültürel ve biyolojik çeşitliliğini oluşturan iskelet ve diş
kalıntıları antropolojik çalışmalar için önemli veriler sunmaktadır. Diş minesi
iskelet kalıntısının en sağlam kısmını oluşturduğu için kötü şartlar altında
kalsa bile incelenebilmektedir. Dişler üzerinden toplumun; beslenme ve yaşam
şekilleri, sosyo-ekonomik durumu gibi birçok konuda aydınlatıcı bilgiler sunar.
Dişler sayesinde geçmişte yaşayan insanlar hakkında toplumlar arası
yakınlık-uzaklık ve varyasyonları da saptanabilir.Buluntulardan elde ettiğimiz
verilere göre o dönemde yaşayan insanların diş sağlığına önem verilmediği
görülmüştür.
ANÁLISE DA APLICAÇÃO DO DELINEAMENTO COMPOSTO CENTRAL EM ENSAIOS DE TRATABILIDADE DA ÁGUA
Authors: Simões Bruna Riguete Vecchi , Goulart Douglas Salles , Combatt Maria Paulina Mendoza , Pimenta João Francisco de Paula , Queiroz Maria Eliana Lopes Ribeiro , Silva Deusanilde de Jesus 
Published: October 2018

Devido aos períodos de crise hídrica nas diferentes Regiões do Brasil é necessário utilizar novas fontes de captação, sendo indispensáveis ensaios de tratabilidade. Foi estudada a viabilidade do uso do Delineamento Composto Central (DCC) nos ensaios de tratabilidade de água como substituição à análise clássica do diagrama de coagulação, por fatorial completo. Os parâmetros de interesse foram a dose de sulfato de alumínio (5 e 60 mg.L-1) e o pH inicial (6 e 8). A variável resposta foi a eficiência de remoção de turbidez. Foi possível maximizar a resposta no ponto de pH inicial de 7,23 e dosagem de 49,9 mg L-1 e encontrar regiões de remoção superior a 80% comuns a ambos os métodos, indicando que o DCC pode ser uma ferramenta viável para análise se comparada com o método convencional, tendo como vantagem a redução da quantidade de ensaios e, consequentemente, o tempo de operação.
ESTUDO DE VIABILIDADE ECONÔMICA DO APROVEITAMENTO COMERCIAL DE AREIA RETIDA NO TRATAMENTO PRELIMINAR DA ETE ONÇA –MG
Authors: Silva Warley Ruas , Poague Kasandra Isabella Helouise Mingoti , Nunes Julia Chaves Silva 
Published: October 2018

O reuso de subprodutos advindos do tratamento de esgotos sanitários é uma temática que vem crescendo cada vez mais atualmente. Esse trabalho tem como objetivo realizar uma avaliação econômica da reutilização da areia proveniente do tratamento preliminar da Estação de Tratamento de Esgoto do Ribeirão do Onça (ETE Onça). Para isso foram avaliadas as etapas necessárias para esse reuso que seriam: lavagem, secagem, controle de odor e proliferação de vetores e higienização. Para a lavagem utilizou-se um lavador de areia. Na secagem optou-se por utilizar pátios de secagem já construídos na ETE. Para o controle de odor, proliferação de vetores e higienização foi calculada uma adição de cal. Entre os gastos e ganhos advindos da venda da areia estimou-se que a partir do 20º mês a ETE já haveria recuperados os gastos iniciais e ao final de 2 anos conseguiria um lucro total de R$46.259,33.
The Effect of Corruption on International Trade: A Case Study of Indonesian Trade to Nine Countries
Authors: Atsir Danang Ibnu , Sunaryati Sunaryati 
Published: October 2018

Corruption is a form of abuse of ethical authority by public officials, which is divided into two parts: bribery and forced collection. The effect of corruption like bribes and illegal levies is widespread in the public sector. One interesting investigation is the effect of corruption on international trade. Corruption becomes a barrier in international trade, where corruption plays a role in the access of trade goods and services from within and abroad. Using the gravity model, the focus of this research was the effect of corruption on international trade by taking a case study of Indonesia’s bilateral trade with its nine largest export destination countries. Using panel data, analysis tools used in this research were common effect, fixed effect, random effect and poisson pseudo maximum likelihood (PPML). In this research, it was found that geographical distance variable in its fixed units caused the omitted variable so that the error term correlated with independent variables. In order to overcome the problem, poisson pseudo maximum likelihood method was used in performing regression gravity model with linear log form, so the omitted variable issue on the geographical distance can be eliminated. The results of this research concluded that corruption played a role in international trade through bureaucratic mechanisms of trade and investment licensing and the effect of corruption was more detrimental to exporters.Keywords: Gravity Model, Corruption, International Trade, Poisson Pseudo Maximum Likelihood (PPML).
Complications Associated with Volar Locking Plate Fixation of Distal Radial Fractures
Authors: Alter Todd H. , Ilyas Asif M. 
Published: October 2018

* Volar locked plating is the most frequently utilized method for internal fixation of distal radial fractures.* The overall complication rate for volar plating of distal radial fractures appears to be relatively low compared with other operative fixation methods.* Carpal tunnel syndrome is the most commonly reported complication. However, this may occur after a distal radial fracture regardless of treatment method, with reported rates ranging from 0% to 20% with conservative management and 0% to 14% with volar plating.* Extensor tendon rupture has been reported at rates of 0% to 4% and is the most frequent complication requiring plate removal.* Variable-angle volar locking plates may be associated with fewer implant-related complications as a result of their greater degree of screw placement customization compared with fixed-angle volar locking plates.
Soil Carbon and Nitrogen under Bioenergy Forage Sorghum Influenced by Cover Crop and Nitrogen Fertilization
Authors: Sainju Upendra M. , Singh Hari P. , Singh Bharat P. , Chiluwal Anuj , Paudel Rajesh 
Published: October 2018

Core Ideas
Removal of aboveground biomass may affect soil C and N under forage sorghum.
Effect of cover crop and N on soil C and N and sorghum biomass were examined.
Soil organic C, soil total N, and sorghum biomass were greater with vetch–rye than other cover crops.
Ammonium‐N was greater with rye and nitrate‐N greater with vetch and vetch–rye.
Vetch–rye can enhance soil C and N storage, N availability, and forage sorghum biomass.
Sustaining soil C and N under bioenergy forage sorghum (Sorghum vulgare Pers.) may require cover crop C and N inputs. We evaluated the effect of cover crop (hairy vetch [Vicia villosa Roth], rye [Secaele cereale L.], hairy vetch–rye mixture, and the control [no cover crop]) and N rate (0 and 90 kg N ha–1) to forage sorghum on soil C and N. Soil samples collected from the 0‐ to 30‐cm depth after sorghum harvest in the autumn were analyzed for soil organic C (SOC), total N (STN), NH4–N, and NO3–N contents from 2010 to 2014 in the southeastern United States. Cover crop biomass and C and N contents were 60% greater with vetch–rye than rye and the control in 2013 and 2014. Forage sorghum biomass was 23% greater with vetch–rye than rye and vetch in 2012 and 7% greater with 90 than 0 kg N ha–1. At 0 to 5 and 0 to 30 cm, SOC was 16% greater with vetch–rye than rye and vetch and STN 15% greater with vetch, rye, and vetch–rye than the control at 0 kg N ha–1. Compared with other cover crops, NH4–N content at 5 to 15 cm was 40% greater with vetch and rye and NO3–N content at 0 to 30 cm was 20% greater with vetch and vetch–rye in 2011 and 2012. Because of increased C and N inputs, hairy vetch–rye cover crop mixture can enhance soil C and N storage, optimize N availability, and sustain forage sorghum biomass compared with other cover crops.
Late‐Season Bermudagrass Control with Glyphosate, Fluazifop, and Mesotrione Combinations
Authors: Hoyle Jared A. , Braun Ross C. , Thompson Cole S. , Reeves Jacob A. 
Published: October 2018

Core Ideas
More information is needed to improve late‐season bermudagrass control strategies in the Central Plains region of the United States.
A single autumn application of glyphosate reduces bermudagrass cover the following spring.
Bermudagrass control with a single autumn application of glyphosate was not improved by adding fluazifop, mesotrione, or both.
Multiple summer applications of glyphosate (N‐(phosphonomethyl)glycine) are commonly recommended for bermudagrass (Cynodon spp.) control. However, this regime results in an extended period of displeasing and nonfunctional turfgrass, and is not ideal for spring establishment. An autumn glyphosate application prior to winter dormancy can control bermudagrass and may benefit spring establishment projects. However, research is needed to more precisely define the parameters of efficacious late‐season herbicide applications for bermudagrass control as it transitions into dormancy. Therefore, our objective was to examine late‐season bermudagrass removal using combinations of glyphosate, fluazifop‐p‐butyl (fluazifop) (Butyl (R)‐2‐[4[[5‐(trifluoromethyl)‐2‐pyridinyl]oxy]phenoxy]propanoate), and mesotrione (2‐(4‐methylsulfonyl‐2‐nitrobenzoyl)‐1,3‐cyclohexanedione). Experiments were initiated in October 2013 at the Rocky Ford Turfgrass Research Center in Manhattan, KS, on mature ‘Midlawn’ hybrid bermudagrass [Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt‐Davy], and at Stagg Hill Golf Course in Manhattan, KS, on mature common bermudagrass [C. dactylon (L.) Pers.]. Seven herbicide treatments containing combinations of glyphosate, fluazifop, and mesotrione were evaluated. Green bermudagrass cover (0–100%) was visually estimated when treatments were applied and every 14 d after application. Only treatments containing glyphosate reduced the green cover of bermudagrass at each site the following year. Across all ratings dates and locations, adding mesotrione, fluazifop, or both to glyphosate did not further reduce green bermudagrass cover. Overall, results indicate that a single autumn application of glyphosate prior to bermudagrass dormancy reduces bermudagrass cover the following spring. The significant reduction at spring green‐up may allow turf managers to make additional applications in the spring for increased control before spring establishment.
The Effect of Fallow Tillage Management on Aeolian Soil Losses in Semiarid Central Anatolia, Turkey
Authors: Nouri Amin , Youssef Feras , Basaran Mustafa , Lee Jaehoon , Saxton Arnold M. , Erpul Gunay 
Published: October 2018

Core Ideas
Eliminating fallow tillage increased the natural plant cover at the soil surface.
Increased natural plant cover did not significantly decrease the aeolian soil losses.
Event‐based vertical distribution of soil losses were related to the upwind plant characteristics.
Accounting for plant configuration improved the prediction of vertical soil flux distribution.
In semiarid Central Anatolia Turkey, winter wheat (Triticum aestivum L.) planted under a conservation tillage system undergoes a no‐till fallow phase to reduce aeolian soil losses by maintaining the natural plant cover. This research was conducted to investigate the effectiveness of natural vegetation cover in relation to tillage‐induced soil surface properties in reducing the wind erosion during the fallow periods. Climatic parameters at experimental plots subjected to no fallow tillage (NFT) and conventional fallow tillage (CFT) (disk) managements were measured and friction velocity (u*) and aerodynamic roughness (z0) over four high wind events (wind velocities >5.7 ms−1 at 2 m high) were determined. Sediment fluxes at each management were measured using 20 sampling posts each holding five vertically placed sediment traps. Spatial dynamics of soil fluxes were related to the soil surface properties and the vegetation characteristics (coverage and configuration). Spatial variations in upwind vegetation characteristics were significantly (p < 0.05) related to the mass fluxes up to 40 cm above the soil surface. However, greater vegetation cover in NFT did not result in significant reductions in mass transport rate compared with CFT. This can be explained by substantially greater (>360%) loose material in NFT due to the dissipation of wheat residue during the early fallow period (23% in late March) and longer transport distance due to a lower surface roughness. These results corroborate that the elimination of fallow tillage alone may not generate sufficient natural vegetation cover to effectively reduce aeolian soil losses in fallow periods of winter wheat cropping systems.
Consistency of the Threshold Phosphorus Saturation Ratio across a Wide Geographic Range of Acid Soils
Authors: Dari Biswanath , Nair Vimala D. , Sharpley Andrew N. , Kleinman Peter , Franklin Dorcas , Harris Willie G. 
Published: October 2018

Core Ideas
Establish a common threshold in P saturation across a geographic diversity of soils.
Predict water‐soluble P from soil P storage capacity to guide fertilizer strategies.
Relate runoff P concentration with soil P storage capacity.
Loss of legacy soil phosphorus (P) due to historical over‐application of fertilizers and manures can result in eutrophication of water bodies. The soil P storage capacity (SPSC) has been proposed as a tool to estimate the capacity of humid region soils to act as either sinks or sources of P to runoff or leaching. The SPSC is based on a threshold molar ratio of extractable P/(Al+Fe), called the soil P saturation ratio (PSR), above which water‐soluble P abruptly increases. Objectives were to (i) document consistency of the threshold PSR for a wide geographic range of acid soils, (ii) determine applicability of a SPSC vs. water‐soluble P predictive equation to soils from various regions, and (iii) relate SPSC with water quality parameters. Surface samples were collected from acidic, humid‐region soils encompassing multiple physiographic provinces of the United States. Water quality data, including dissolved reactive P and total P, were obtained from various study sites. Phosphorus, Fe, and Al in Mehlich 3 solutions were determined, and PSR and SPSC calculated. The threshold PSR based on 186 samples is 0.1, indicating a common threshold across the geographic range of this study. Phosphorus concentrations in runoff related closely with SPSC, PSR, and M3‐P values of soils that were the source of the runoff. However, SPSC has the additional potential of estimating extent of legacy P loss at excessive concentrations for soils of eastern and central United States. Results support general applicability of PSR and SPSC for acid soils.