Online measurement of soil organic carbon as correlated with wheat normalised difference vegetation index in a vertisol field

This study explores the potential of visible and near infrared (vis-NIR) spectroscopy for onlinemeasurement of soil organic carbon (SOC). It also attempts to explore correlations and similarities between the spatial distribution of SOC and normalized differential vegetation index (NDVI) of a wheat crop. The online measurement was carried out in a clay vertisol field covering 10 ha of area in Karacabey, Bursa, Turkey. Kappa statistics were carried out between different SOC and NDVI data to investigate potential similarities. Calibration model of SOC in full cross-validationresulted in a good accuracy ( 2 = 0.75, root mean squares error of prediction (RMSEP) = 0.17%, and ratio of prediction deviation (RPD) = 1.81). The validation of the calibration model using laboratory spectra provided comparatively better prediction accuracy ( 2 = 0.70, RMSEP = 0.15%, and RPD = 1.78), as compared to the online measured spectra ( 2 = 0.60, RMSEP = 0.20%, and RPD = 1.41). Although visual similarity was clear, low similarity indicated by a lowKappa value of 0.259 was observed between the online vis-NIR predicted full-point (based on all pointsmeasured in the field, e.g., 6486 points)map of SOC and NDVI map

On-line Vis-Nir sensor determination of soil variations of sodium, potassium and magnesium

Among proximal measurement methods, visible and near infrared (Vis-Nir) spectroscopy probably has the greatest potential for determining the physico-chemical properties of different natural resources, including soils. This study was conducted to determine the sodium, potassium and magnesium variations in a 10. Ha field located in Karacabey district (Bursa Province, Turkey) using an on-line Vis-Nir sensor. A total of 92 soil samples were collected from the field. The performance and accuracy of the Na, K and Mg calibration models was evaluated in cross-validation and independent validation. Three categories of maps were developed: 1) reference laboratory analyses maps based on 92 points 2) Full-data point maps based on all 6486 on-line points Vis-Nir predicted in 2013 and 3) full- data point maps based on all 2496 on-line points Vis-Nir predicted in 2015. Results showed that the prediction performance in the validation set was successful, with average R2 values of 0.82 for Na, 0.70 for K, and 0.79 for Mg, average root mean square error of prediction (RMSEP) values of 0.02% (Na), 0.20% (K), and 1.32% (Mg) and average residual prediction deviation (RPD) values of 2.13 (Na), 0.97 (K), and 2.20 (Mg). On-line field measurement was also proven to be successful with validation results showing average R2 values of 0.78 (Na), 0.64 (K), and 0.60 (Mg), average RMSEP values of 0.04% (Na), 0.13% (K), and 2.19% (Mg) and average RPD values of 1.57 (Na) 1.68 (K) and 1.56 (Mg). Based on 3297 points, maps of Na, K and Mg were produced after N, P, K and organic fertilizer applications, and these maps were then compared to the corresponding maps from the previous year. The comparison showed a variation in soil properties that was attributed to the variable rate of fertilization implemented in the preceding year

Evaluation of tool life - tool wear in milling of Inconel 718 superalloy and the investigation of effects of cutting parameters on surface roughness with Taguchi method

U ovom se radu istraživalo djelovanje brzine rezanja, smjera glodanja (prema dolje, prema gore), sloja premaza (TiAlN i TiAlN-TiN) i broja umetaka držača alata na površinsku hrapavost i trajanje alata kod suhog glodanja superlegure Inconel 718. U prvom su se redu proučavali učinci kontroliranih faktora na radni vijek alata pri brzinama rezanja od v = 50 m/min i v = 100 m/min. Ispitivala se promjena površinskog trošenja ovisno o brzini rezanja. Tipovi trošenja i mehanizmi trošenja su se određivali ispitivanjem optičkih slika istrošenih alata. U drugom dijelu rada, kako bi se istražilo djelovanje kontrolnih faktora na hrapavost površine, primijenjena je L16 Taguchi metoda te su određeni optimalni nivoi kontrolnih faktora, dajući najnižu vrijednost prosječnog parametra hrapavosti površine (Ra). Brzina rezanja je imala veći učinak na vijek trajanja alata nego što su to imali način glodanja i broj umetaka. Glodanje prema dolje je rezultiralo duljim trajanjem alata u usporedbi s glodanjem prema gore. Kod glodanja prema gore dulji radni vijek alata je postignut s 2 umetka pri malim brzinama rezanja, a s 4 umetka pri velikim brzinama rezanja. Pokazalo se da alati obloženi TiAlN-TiN premazom imaju dvostruko dulji radni vijek nego alati obloženi TiAlN premazom. Kod obje metode glodanja najučinkovitije vrste trošenja bile su površinsko trošenje i trošenje vrha alata.In this study, the effects of cutting speed, milling direction (down milling, up milling), coating layer (TiAlN and TiAlN-TiN) and the number of inserts of tool holder on the surface roughness and tool life in dry milling of Inconel 718 superalloy were investigated. In the first place, the effects of control factors on the tool life were studied at the cutting speeds of v = 50 m/min and v = 100 m/min. The alternation of flank wear depending on the cutting time was examined. The types of wear and wear mechanisms were determined by examining the optical images of worn tools. In the second part of the study, for the purpose of investigating the effects of control factors on the surface roughness, L16 Taguchi Technique was used and the optimal control factor levels, giving the lowest value of the average surface roughness parameter (Ra) were determined. The effect of cutting speed on the tool life was more than the effects of the milling type and number of inserts. Down milling resulted in longer tool life compared to up milling method. In up milling, longer tool life was obtained with 2 inserts at low cutting speeds and with 4 inserts at high cutting speeds. TiAlN-TiN coated tools exhibited twice as long tool life than the TiAlN coated tools. For both milling methods, the most effective wear types were flank wear and nose wear

Potential of on-line visible and near infrared spectroscopy for measurement of pH for deriving variable rate lime recommendations

This paper aims at exploring the potential of visible and near infrared (vis-NIR) spectroscopy for on-line measurement of soil pH, with the intention to produce variable rate lime recommendation maps. An on-line vis-NIR soil sensor set up to a frame was used in this study. Lime application maps, based on pH predicted by vis-NIR techniques, were compared with maps based on traditional lab-measured pH. The validation of the calibration model using off-line spectra provided excellent prediction accuracy of pH (R2 = 0.85, RMSEP = 0.18 and RPD = 2.52), as compared to very good accuracy obtained with the on-line measured spectra (R2 = 0.81, RMSEP = 0.20 and RPD = 2.14). On-line predicted pH of all points (e.g., 2,160) resulted in the largest overall field virtual lime requirement (1.404 t), as compared to those obtained with 16 validation points off-line prediction (0.28 t), on-line prediction (0.14 t) and laboratory reference measurement (0.48 t). The conclusion is that the vis-NIR spectroscopy can be successfully used for the prediction of soil pH and for deriving lime recommendations. The advantage of the on-line sensor over sampling with limited number of samples is that more detailed information about pH can be obtained, which is the reason for a higher but precise calculated lime recommendation rate

Determining energy requirements of some seedbed preparation implements

Tarımsal üretimde birim alandan elde edilen ürün miktarını artırmada teknolojik uygulamaların giderek ağırlık kazanması daha fazla eneıji kullanmayı gerektirmiştir. Gelecekte tarım makinalarının eneıji yönetimi büyük önem kazanacaktır. Enerji yönetimine ait kararlar için de aletlerin çeki kuvvetlerinin bilinmesi gerekmektedir. Tarımsal işlemlerde verimliliği artırabilmek için traktör ve kullanılan alet arasındaki kuvvetlerle ilgili detaylı bilgilere gereksinim duyulmaktadır. Toprak işlemede çeki kuvvetleri gereksiniminin tahmini için sayısal uygulama modelleri geliştirilmiş olmakla beraber, bu modellerin iyileştirilebilmesi için tarla çalışmalarında alınan verilere gereksinim vardır. Bu araştırmada U.Ü.Z.F. Araştırma ve Uygulama Çiftliğinde kulaklı pulluk, diskli tırmık, kültivatör, dişli tırmık gibi toprak işleme aletleri ile farklı çalışma hızlarında çeki kuvveti, çeki hızı, patinaj gibi işletmecilik açısından gerekli bazı veriler ölçülmüştür. Çeki kuvveti ölçümlerinde çift traktör yöntemi kullanılmıştır. Araştırmada, her bir toprak işleme aleti için çalışma hızının artmasıyla söz konusu aletlerin çekilebilmesi için gerekli olan çeki kuvvetinin arttığı bulunmuştur. İki toprak tipi ele alındığında, denenen toprak işleme aletleri için toprak sıkışıklığı değerinin büyük olduğu tarlada gereksinim duyulan çeki kuvvetlerinin daha büyük olduğu saptanmıştır.To increase amount of crops from the unit field in agricultural production by repiacİng in to new technology is needed to be use more energy. Energy management of agricultural machinery will be increasingly İmportant in the fiıture. Draft requirements will also be required for energy management decision. To improve productivity in farm operations; it is necessary to have detailed information about the forces between tractors and implements. In order to estimate tillage energy requirements, attempts have been made by using numerical models, however, field practices must be adapted to collect data so that models can be evaluated. This research describes the basic farm machinery management data such as draught forces, speed and slippage for moldboard plough, disk harrow, cultivator and spike tooth harrow under different working speed in Application and Research Farm of Agriculture Faculty of Uludağ University. Twin tractor method has been used to measure draught forces of implements. Results showed that draught requirements increased with increasing the working speed for soil tillage equipments. At the two types of soil; such as clay and sandy loam, it was found that the draught force requirements are higher in the compacted soil conditions for every tillage implemen

Using possibilities of tractor hydrolic driven soil penetrometer for measuring soil compaction

Toprak sıkışıklığı bazı durumlarda bitkilerde büyümeyi ve kök gelişimini sınırlayan önemli bir fiziksel sınırlayıcı faktör olarak karşımıza çıkmaktadır. Bu yüzden bitkilerin yetiştirilme sezonunda yoğun tarla trafiğine bağlı olarak oluşan toprak sıkışıklığının kontrol edilmesi gerekmektedir. Tarla koşullarında oluşan toprak sıkışıklığı değerleri genellikle standart olan farklı tasarımlardaki toprak penetrometreleri kullanılarak belirlenir. Toprak penetrometrelerinin yaygın kullanımı delmi ve bush tipi standart el penetrometleri ile yapılmakta olup, toprak sıkışıklığı koni indeksi olarak bu penetrometrelerin konisinin toprağı standart delme hızında penetrometreye uygulanan kuvvetin koninin taban alanına oranlanması ile saptanır. Çoğu uygulamalarda, özellikle ağır toprak şartlarında standart el penetrometresi ile toprak sıkışıklığı değerlerinin ölçülmesi sırasında, sabit delme hızını oluşturacak kuvvet uygulanamadığından ölçümde hatalar oluşmaktadır. Aynı zamanda el penetrometreleri ile toprak sıkışıklığının ölçümü yorucu olmakta ve oldukça fazla zaman almaktadır. Bu yüzdendir ki, toprak sıkışıklığına ilişkin ölçümlerde zamanı en aza indirebilmek ve ölçülerdeki olası hata payım azaltabilmek için traktör üç nokta askı sistemine bağlanarak çalışan hidrolik tahrikli bir toprak penetrometresi imal edilmiştir. Üç nokta askı sitemine asılacak şekilde geliştirilen bu penetrometrede, kullanılan bir hidrolik piston, penetrometre konisini standart hızda toprağı delecek şekilde itmektedir. Koniye uygulanan kuvvet, bir yük hücresi, 16 bit'lik veri toplama birimi, sinyal yükseltici, dizüstü bilgisayar ve gerekli veri kontrol yazılımından oluşan bir sistem ile ölçülmektedir. Bu sistem ile veri toplama hızı saniyede 10 adet verinin alınması şeklindedir. Maksimum yük hücresi kapasitesi doğrusal bölgede 500 kg olup bu değer, bu penetrometre konisi için 6 M Pa'a karşılık gelecek şekilde ayarlanmıştır. Bir köprü devresinden oluşan yük hücresi için uyarm a gerilimi 10 V yapılarak tam skala Ölçüm aralığı 20 m V ’ a yükseltilmiştir. Veri toplama sisteminde aynı zamanda hidrolik sistemle bağlantılı döner elemanlara sahip bir potansiyometreden oluşan derinlik algılayıcısı kullanılmıştır. Derinlik algılayıcısının doğrusal bölgedeki kalibrasyonuna göre minimum ilerleme gerilimi 1.4 mV/° dir. Penetrometre çubuğunun 30mm/s standart hızda toprağı delebilmesi, 3 L/d kapasiteli akış kontrol valfı tarafından sağlanmaktadır.The soil compaction sometimes bccomes an important physical limiting factors for the root emergence and the growth o f plants. Therefore, it is essential to control soil compaction that is normally caused by heavy traffic on field during to the growing season. The soil compaction in field is usually measured by using Standard soil cone penetrometers that can be several types due to their design. For common applications, Standard hand penetrometers such as delmi and bush types are used, and the soil compaction is presented as cone index which is the force acting on device handle divided by Standard cone base area during to the penetration o f penetrometer cone for the constant penetration rate. Most o f the time, especially, in heavy soil conditions, measuring the soil compaction with a Standard hand penetrometer produces measurement errors if the cone of penetrometer cannot be pushed in to the soil with Standard rate. Obtaining data is also difficult and takes long time and cffort with hand penetrometers. For this reason, a three-point hitch mounted and hydraulic driven soil cone penetrometer has been designed in order to reduce time and effort and to reduce possible measurement errors for the sampling o f soil compaction data for research purposes. The hydraulic penetrometer is mounted on threc hitch points and an hydraulic piston pushes Standard penetrometer cone in to the soil in constant speed. Forces acting on cone base are recorded with a Computer based 16-bit data acquisition system that is composed on a load celi, a portable Computer, signal amplifîer and necessary control sofhvare for the sampling. The time o f data sampling is calibrated as ten readings per second. The maximum load celi capacity in linear region is 500 kg that corresponds 6 MPa. An A/D converters card provides 10 V direct current to excite the load celi that is an actually bridge Circuit. Its sensitivity is approximately 2mV, and the minimum measurement interval is 0.8 kg per mV for the calibration. The system also includes a soil depth sensor that is made as tuming electronic potentiometer placed on an hydraulic cylinder. The rotation o f the potentiometer is sensed as a linear movement in 1.4 mV/° per mm length as the depth sensor calibration. The constant penetration rate o f the soil penetrometer cone is 30 mm/s, and a control valve that has maximum capacity as 3 L/min provides this speed.Uludağ Üniversitesi Araştırma Fon