Open Access Original Research Article

Spatial Evaluation of Droughts Using Selected Satellite-based Indices in the Upper Tana River Watershed, Kenya

Harriette A. Okal, Felix K. Ngetich, Jeremiah M. Okeyo

International Journal of Plant & Soil Science, Page 1-13
DOI: 10.9734/ijpss/2019/v30i130164

Aims: To identify the most appropriate drought indices for the identification and monitoring of historical meteorological and agricultural drought incidences and to explore the spatial characteristics of these droughts.

Study design: GIS-based empirical research design.

Place and Duration of Study: Upper Tana River Watershed, Kenya drought analysis covering a period of 1981 to 2013.

Methodology: National Oceanic and Atmospheric Administration-Advanced Very High Resolution Radiometer (NOAA-AVHRR) provided raster maps for Normalized Difference Vegetation Index (NDVI) agricultural drought index, while GeoClim databased through Climate Hazards Group InfraRed Precipitation with Station data (CHIRPS) was used for retrieval of raster maps for Standardized Precipitation Index (SPI) meteorological drought index. ArcGIS version 10.3.1 facilitated image enhancement and correction for better visualization and interpretation.

Results: Agricultural drought years were in 1983, 1987, 1993, 1996, 2000, 2004, 2005, 2008, and 2009 while meteorological drought years were in 1983, 1984, 1992, 1996, 1999, 2002, 2003, and 2011.

Conclusion: Meteorological drought triggered events of agricultural drought. Both droughts showed a widespread pattern and were found to manifest at relatively same intervals during the study period.

Open Access Original Research Article

Germination under High Temperatures of Maize Adapted to the Cerrado of Tocantins

Kassya Silveira Barbosa, Luiz Felipe Soares Aguiar, Susana Cristine Siebeneichler, Aurélio Vaz de Melo, Adriano Silveira Barbosa, Álida Filomena Andrade, Laina Pires Rosa, Magno De Oliveira

International Journal of Plant & Soil Science, Page 1-10
DOI: 10.9734/ijpss/2019/v30i130165

The purpose of this study was to evaluate the response of germination and vigor in maize seeds in laboratory conditions, exposure to high temperatures, in order to highlight the most adaptable genotypes at these temperatures. Were supplied three cultivars of the PIONEIRA LTDA. (PIONEIRA HS-9, PIONEIRA HS-14i, PIONEIRA ROBUSTO), to perform the experiment, in addition to the commercial cultivar BRS 3040. After the selection of superior genotypes, were performed at temperatures of 25 reviews, 30, 35 and 40ºC, these being: germination, first count, seedling dry mass and speed index of the emergence of seedlings. At the temperature of 25°C were made the cold test and seedling length, shoot and root axis. The results were submitted to analysis of variance, comparison of averages by Tukey test, to three genotypes and regression analysis to high school, to three genotypes and the witness commercial. Whereas the maximum temperature of 35°C tested, one could observe that the PIONEIRA HS-6 genotype presented the best adaptation to high temperatures. The PIONEIRA ROBUSTO genotype was more adapted to high temperatures whereas as the highest temperature of 40°C. The BRS 3040 was not adapted to the high temperatures in relation to genotypes produced under conditions of high temperatures of the Cerrado.

Open Access Original Research Article

Application of GIS on the Identification of Suitable Areas for Water Conservation Technologies in the Upper Tana Watershed of the Central Highlands of Kenya

B. W. Nganga, K. O. Nge’tich, N. Adamtey, K. Milka, K. F. Ngetich

International Journal of Plant & Soil Science, Page 1-20
DOI: 10.9734/ijpss/2019/v30i130166

Low adoption of soil water conservation technologies has been one of the main causes for decreased agricultural productivity in the Upper Tana Catchment of Kenya. Proper identification of locations to scale-out the individual technologies necessary to improve water conservation is a key determinant for the rate of adoption. Our main aim was to identify the suitable sites for water conservation technologies using the suitability model created by the model builder function in ArcGIS 10.5®. The model combined the thematic layers of soil texture, slope, rainfall, and stream order, which were acquired from assorted online sources. The factors were converted to raster format and reclassified based on their suitability and were assigned fixed scores and weights by use of multi influencing factor (MIF) method. The suitability evaluation was carried out by use of weighted overlay to produce suitability classes for each of the water conservation technique. The delineated suitability maps indicated that check dams are highly suitable in 50% of the study area. Mulching, on the other hand, is highly suitable for 49% of the study area. Zai pits are highly suitable in 43% of the study area. Majority of the study area is moderately suitable for the use of terraces, covering 41% of the study area. The highly suitable areas for the Checkdams are Machakos, Kitui, Tharaka-Nithi and lower parts of Embu. The highly suitable areas for mulching are Kirinyaga, Murang’a, Nyandarua and Nyeri. The highly suitable areas for the Zai pits are Kitui, lower parts of Tharaka-Nithi and the highly suitable areas for the terraces are Murang’a, Nyeri and Kirinyaga. Furthermore, the results demonstrated the effectiveness of GIS in delineating the suitable areas for the use of water conservation technologies.

Open Access Original Research Article

Investigating the Phenological and Pompological Characteristics of Indigenous Pears in Northeast Bosnia

Besim Salkić, Ramzija Cvrk, Emir Imširović, Amela Jašić, Ahmed Salkić

International Journal of Plant & Soil Science, Page 1-11
DOI: 10.9734/ijpss/2019/v30i130167

The study included 30 autochthonous pears with analysis of the following parameters: blooming time, fruit ripening time, fruit weight, fruit height, fruit width, fruit index, fruit juice length, pH value of juice, total acidity mmol / 100 g, total acidity (%), pectin substances % Ca-pectate, raw fiber %, vitamin C mg / 100 g, natural invert sugar%, total invert sugar %, total phenol mg / 100 g fruit, soluble dry substance (° Brix).The aim of the research is to study the phenological and pomological characteristics of a detailed description of autochthonous varieties and to make chemical analysis of the fruit of a recommendation on the value of the fruit of the most interesting autochthonous pears in north-eastern Bosnia. This would at the same time create preconditions for recording these varieties on the sort list of Bosnia and Herzegovina and their further reproduction and marketing.The fruits of domestic varieties are seldom available. Given the opinion that domestic varieties are more resistant to diseases and some pests, they do not require a large number of chemical treatments and require no intensive care can be more easily adapted to organic cultivation, which is a trend in fruit productionThe differences in the blooming dynamics of autochthonous varieties of BiH indicate that this is an important detail that must be take care  when expanding them, that is, introducing them into plantation cultivation and selecting pollinator varieties. The obtained values of soluble dry matter for all tested pear varieties (except Kajzerica kasna 9.75 Brix) had a value greater than 10.0˚ Brix, and according to this parameter, are suitable for marketing and processing according to the current legislation. The native varieties examined in this paper had values from 0.10 to 0.58% from the results of the analysis, it can be concluded that the tested varieties were not supplied with Ca-pectate. Based on the average content of vitamin C in the fruit of the pear, it can be concluded that the tested  autochthonous  and domestic varieties have an extremely good content of vitamin C, 15 out of 20 varieties have a higher content of vitamin C than the average or 75%. Research has been supported by the Federal Ministry of Education and Science within the framework of a scientific research project entitled "Investigating the phenological and pompological characteristics of indigenous pears in Northeast Bosnia".

Open Access Original Research Article

Quantifying Effects of Selected Soil Fertility Management Techniques on Water Use Efficiency in the Central Highlands of Kenya

Beryl Etemesi, Felix K. Ngetich, Milka N. Kiboi, Abdi Zeila, Noah Adamtey, Daniel N. Mugendi

International Journal of Plant & Soil Science, Page 1-11
DOI: 10.9734/ijpss/2019/v30i130168

Declining rainfall distribution and variability lead to low soil moisture amounts and high evapotranspiration rates reducing water use efficiency that negatively affects crop productivity. Various soil fertility management techniques have been put in place to improve soil fertility status, but there is little attempt to asses their effects on water use efficiency and grain yields. The overall objective of the study was to quantify the effects of soil fertility management techniques on water use efficiency in the Central Highlands of Kenya. The experiment was laid out in a randomised complete block design with fourteen treatments replicated four times. Treatments were sole mineral fertilizer (Rf), crop residues + mineral fertilizer (RMf), crop residues + mineral fertilizer + animal manure (RMfM), crop residue + Tithonia diversifolia + animal manure (RTiM), crop residue + Tithonia diversifolia + rock phosphate (RTiP). Data on yield and water use efficiency was analysed using statistical analysis systems software version 9.2 at P=0.05. We observed significant (P<.0001) effect of the treatment on biomass water use efficiency during the short rains 2017, however, there was no significant effect of the treatments on grain water use efficiency because of the frequent dry spells that occurred during the study period. Soil fertility management techniques had a significant effect on grain yield at P<.0001 during the study period. Yields increased significantly (P<0001) under Rf, RMf, RMfM RTiM and RTiP by 90, 110, 120, and 176%, respectively. Water use efficiency also increased significantly under Rf, RMf, RMfM RTiM and RTiP by 200, 140, 180, 129, and 176%, respectively compared to the control. From the study, the combination of organic inputs and mineral fertilisers enhanced water use efficiency and yield hence provides a preferred practise for improved water use efficiency and yield increase.