Application of Discriminant Analysis Techniques to Determine Soil Fertility Grades

2011 ◽  
Vol 255-260 ◽  
pp. 3018-3021
Author(s):  
Bing Chen Fan

By a method of discriminate analysis, the content of organic matter, alkali hydrolyzadle nitrogen, rapidly available phosphate, rapidly available potassium were used as the identification factors, and soil nutrient data and grain output were analysed. The results of the analysis has indicated that discriminate analysis can determine grades of the soil fertility. The fitting rate was over 80% , and that accuracy of forecast was right. This new method may be tried for determining grades of the soil fertility.

2021 ◽  
Vol 13 (7) ◽  
pp. 3957
Author(s):  
Yingying Xing ◽  
Ning Wang ◽  
Xiaoli Niu ◽  
Wenting Jiang ◽  
Xiukang Wang

Soil nutrients are essential nutrients provided by soil for plant growth. Most researchers focus on the coupling effect of nutrients with potato yield and quality. There are few studies on the evaluation of soil nutrients in potato fields. The purpose of this study is to investigate the soil nutrients of potato farmland and the soil vertical nutrient distributions, and then to provide a theoretical and experimental basis for the fertilizer management practices for potatoes in Loess Plateau. Eight physical and chemical soil indexes were selected in the study area, and 810 farmland soil samples from the potato agriculture product areas were analyzed in Northern Shaanxi. The paper established the minimum data set (MDS) for the quality diagnosis of the cultivated layer for farmland by principal component analysis (PCA), respectively, and furthermore, analyzed the soil nutrient characteristics of the cultivated layer adopted soil quality index (SQI). The results showed that the MDS on soil quality diagnosis of the cultivated layer for farmland soil included such indicators as the soil organic matter content, soil available potassium content, and soil available phosphorus content. The comprehensive index value of the soil quality was between 0.064 and 0.302. The SPSS average clustering process used to classify SQI was divided into three grades: class I (36.2%) was defined as suitable soil fertility (SQI < 0.122), class II (55.6%) was defined as moderate soil fertility (0.122 < SQI < 0.18), and class III (8.2%) was defined as poor soil fertility (SQI > 0.186). The comprehensive quality of the potato farmland soils was generally low. The proportion of soil nutrients in the SQI composition ranged from large to small as the soil available potassium content = soil available phosphorus content > soil organic matter content, which became the limiting factor of the soil organic matter content in this area. This study revolves around the 0 to 60 cm soil layer; the soil fertility decreased gradually with the soil depth, and had significant differences between the respective soil layers. In order to improve the soil nutrient accumulation and potato yield in potato farmland in northern Shaanxi, it is suggested to increase the fertilization depth (20 to 40 cm) and further study the ratio of nitrogen, phosphorus, and potassium fertilizer.


2018 ◽  
Vol 3 (02) ◽  
pp. 108-115
Author(s):  
S. P. Vista ◽  
T. B. Ghimire ◽  
T. S. Rai ◽  
B. S. Kutu ◽  
B. K. Karna

Potato is a staple food crop in high hills and mountains and a major vegetable throughout the country and one of the most important cash generating crops in Nepal. With the efforts undertaken by research and extension sectors, its productivity has significantly increased in last twenty years. However, this is not sufficient for increasing population of the country. Considering its potentiality for income, employment, industrial products, export and processing, appropriate technologies are urgent.Soil fertility evaluation is the most basic decision making tool for the sustainable soil nutrient management. Soil fertility studies and mapping is an effective way to diagnose soil status and recommend as per the need of the nutrient to particular crop in the area. This research aims to assess and prepare soil nutrient map of potato super zone, Kavrepalanchowk in Nepal. The specific objectives of the research were to assess soil texture, pH and organic matter status and simultaneously prepare soil fertility map of the potato super zone. A total of 202 soil samples were collected and nutrients were analyzed using standard procedure in the soil laboratory. Composite soil samples were collected from 6 to 10 different spots of the area at 0-20 cm depth by using soil auger. The GPS location of each soil sampling point was noted. The soil sampling point of each zone was determined by studying various aspects (area, slope, colour, texture, etc.) of the study area. Based on the nutrient status, nutrient maps were prepared and presented. Soil fertility maps were prepared by observing the critical nutrients required for the specific crops and by giving those nutrients certain ranking based on the nutrients role for the crop. The soil of Potato super zone was mostly found to be silty loam, moderately acidic (pH 5.9), medium in organic matter content (2.67%) and total nitrogen (0.13%), high in available phosphorus content (56 kg/ha) and available potassium (356kg/ha). There is also sandy loam, loam and silty clay loam types of soil in the area. Soil fertility maps were prepared by setting criteria based on nutrient status that were tested in the laboratory and on the basis of nutrients that are critical for each crops of the super zones. Vegetable super zone soil was found having medium (50%) and high (30%) fertility status. Based on the soil analysis report, it could be concluded that the soils of potato super zone is fair enough for cultivating potato crop at the moment.


2021 ◽  
Author(s):  
Mathias Mayer ◽  
Boris Rewald ◽  
Bradley Matthews ◽  
Hans Sandén ◽  
Christoph Rosinger ◽  
...  

CATENA ◽  
2021 ◽  
Vol 207 ◽  
pp. 105611
Author(s):  
Lixin Lin ◽  
Zhiqiu Gao ◽  
Xixi Liu ◽  
Yuan Sun
Keyword(s):  

2015 ◽  
Vol 45 (6) ◽  
pp. 632-638 ◽  
Author(s):  
Kim Bannon ◽  
Sylvain Delagrange ◽  
Nicolas Bélanger ◽  
Christian Messier

Studies have reported divergent results on the effect of soil fertility and canopy opening on understory density and growth of sugar maple (AS; Acer saccharum Marsh.) and American beech (FG; Fagus grandifolia Ehrh.). The main objective of this study was to evaluate the effect of a gradient of canopy opening and soil fertility on the density and growth of AS and FG saplings in southwestern Quebec, Canada. We investigated 56 stands containing both AS and FG that were subjected to different disturbance history types (DHTs) (UF, unmanaged forest; PC, partial cut; and CC, clearcut) on various soil types. AS and FG absolute and relative sapling density varied greatly among the 56 stands; however, no significant effects of DHT, soil nutrient availability, or their interaction were found. Both species responded positively in terms of radial growth to canopy openings, with FG growth being slightly better than AS growth in PC stands compared with other canopy treatments. Contrary to our hypothesis, AS did not show significantly higher growth than FG following clear-cutting. These results do not support the idea that AS abundance and growth could be promoted by increasing the intensity of the canopy opening during harvest, at least on the generally acidic and base-poor soils that were investigated.


2016 ◽  
Vol 68 (12) ◽  
pp. 19-21 ◽  
Author(s):  
Joel Walls ◽  
Tiffany Rider ◽  
Stephanie Perry
Keyword(s):  

2016 ◽  
Vol 41 (4) ◽  
pp. 735-757 ◽  
Author(s):  
NC Shil ◽  
MA Saleque ◽  
MR Islam ◽  
M Jahiruddin

Laboratory studies on soil fertility evaluation was carried out across major agroecological zones (AEZs) of Bangladesh to know the nutrient status of soils and to relate those with soil properties like pH, organic matter, CEC, and clay content. Thirty five composite soil samples were collected from intensive crop growing sites, which covered 17 AEZs of Bangladesh. After proper processing, the samples were analyzed for texture, pH, organic carbon, CEC, exchangeable cations (K, Ca, Mg and Na), total N, available P and S following standard methods. The textural class of the soils collected from AEZ 12 and 13 appeared to be mostly clay. Clay loam soil was found in AEZ 4, 8, 9, 11, 25 and 28. Loamy soil was seen in AEZ 1 while AEZ 22, 23 and 29 were mostly sandy textured. The results revealed that 65.7% of the tested soil was acidic while 25.7% was alkaline in nature. All the tested soils showed lower pHKCl compared to pHH2O thus possessed negative charge. About 68.6% of the collected soils contained low (1.10-1.70%) level of organic matter, 25.7% soils retained it at medium level (1.71-2.40) and 5.7% soils at very low level (<1.0%). All the tested soils appeared to be deficient (< 0.12%) in nitrogen content. 68.6% soil samples had the low level of available P while only 8.6% retained it an optimum amount. About 80% of the tested soils contained low level of available S (7.9- 14.7 mg kg -1) although coastal regions soils hold higher amount of available S. High CEC (20-38 cmol kg-1) was found in clay rich soils of AEZ 10, 11, 12, and 13. Study revealed that 40% of the collected soils were very low, 31.4% were low, 8.6% each of medium and optimum, and 11.4% contained high level of exchangeable K. The calcareous soils (AEZ 10, 11, 12 and 13) contained very high level of Ca. Non calcareous soils also showed fairly good level of Ca content except AEZ 1, 3, 23 and 29. Sandy textured soils of greater Dinajpur, Rangpur, Moulvibazar showed lower level of exchangeable Mg. About 86% of the tested soils had the lower (< 2%) potassium saturation percentage (KSP), which needs K application for sustainable crop production. Estimate showed that 44% variability for CEC may be attributed by clay content and the relationship was significant (p = 0.05). Again, 50.4 and 65.6% variability in exchangeable K and Mg, respectively may be governed by clay content of the soils, while such relationship for Ca was non-significant. CEC may contribute 62.2, 92.3 and 83.9% variability for exchangeable K, Ca and Mg content in soils, respectively. The fertility status of most of the studied soils (except AEZ 10, 12, 13 and to some extent 11) appeared to be low to very low, which demand judicious management in order to achieve food security and to conserve the soil fertility.Bangladesh J. Agril. Res. 41(4): 735-757, December 2016


2009 ◽  
Vol 9 ◽  
pp. 16-22 ◽  
Author(s):  
Bhanu B. Panthi ◽  
Bhupendra Devkota ◽  
Jyoti U. Devkota

Coffee (Coffea arabica; Rubiaceae) is a potential and emerging commercial crop. Coffee is planted in the midhills of Nepal (800 to 1250 meter above mean sea level) in Gulmi and Lalitpur districts. To control the major insect pests of coffee plant, locally prepared ‘jaibik bishadi’ (botanical pesticides) are used as alternatives of the synthetic insecticides. This study was undertaken to see the contribution of ‘jaibik bishadi’ in the fertility of the coffee orchards soil, for which soil samples from botanicals used and not used coffee orchards were collected to see the level of soil characteristics and soil nutrients such as soil texture, organic matter, soil nutrients (phosphorous and potassium). There was some difference in the soil texture of topsoil, but no difference could be seen in sand, silt and clay content of the subsoils from botanical used and not used orchards. The pH was significantly different between botanical used and not used soils, but such difference could not be observed between the topsoil and subsoil from the same sites. Jaibik bishadi used to control the coffee pests significantly contributed in the soil fertility, which could be seen in high positive correlation (r=0.9886) between organic matter and nitrogen in the soil.Keywords: Coffee, jaibik bishadi, topsoil, subsoil, soil fertilityThe Journal of Agriculture and Environment Vol:9, Jun.2008 page: 16-22


Agriculture ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1129
Author(s):  
Yiping Peng ◽  
Lu Wang ◽  
Li Zhao ◽  
Zhenhua Liu ◽  
Chenjie Lin ◽  
...  

Soil nutrients play a vital role in plant growth and thus the rapid acquisition of soil nutrient content is of great significance for agricultural sustainable development. Hyperspectral remote-sensing techniques allow for the quick monitoring of soil nutrients. However, at present, obtaining accurate estimates proves to be difficult due to the weak spectral features of soil nutrients and the low accuracy of soil nutrient estimation models. This study proposed a new method to improve soil nutrient estimation. Firstly, for obtaining characteristic variables, we employed partial least squares regression (PLSR) fit degree to select an optimal screening algorithm from three algorithms (Pearson correlation coefficient, PCC; least absolute shrinkage and selection operator, LASSO; and gradient boosting decision tree, GBDT). Secondly, linear (multi-linear regression, MLR; ridge regression, RR) and nonlinear (support vector machine, SVM; and back propagation neural network with genetic algorithm optimization, GABP) algorithms with 10-fold cross-validation were implemented to determine the most accurate model for estimating soil total nitrogen (TN), total phosphorus (TP), and total potassium (TK) contents. Finally, the new method was used to map the soil TK content at a regional scale using the soil component spectral variables retrieved by the fully constrained least squares (FCLS) method based on an image from the HuanJing-1A Hyperspectral Imager (HJ-1A HSI) of the Conghua District of Guangzhou, China. The results identified the GBDT-GABP was observed as the most accurate estimation method of soil TN ( of 0.69, the root mean square error of cross-validation (RMSECV) of 0.35 g kg−1 and ratio of performance to interquartile range (RPIQ) of 2.03) and TP ( of 0.73, RMSECV of 0.30 g kg−1 and RPIQ = 2.10), and the LASSO-GABP proved to be optimal for soil TK estimations ( of 0.82, RMSECV of 3.39 g kg−1 and RPIQ = 3.57). Additionally, the highly accurate LASSO-GABP-estimated soil TK (R2 = 0.79) reveals the feasibility of the LASSO-GABP method to retrieve soil TK content at the regional scale.


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