Open Access Original Research Article

Effect of Increasing Elevation of Lowland Coastal Saline Soils of Sundarbans (India) on Soil Salinity and Its Seasonal Variation

Tonmoy Sengupta, B. K. Bandyopadhyay, Sudipta Tripathi

International Journal of Plant & Soil Science, Page 1-10
DOI: 10.9734/ijpss/2019/v29i530152

The delta region of the river Ganges spreads over India (West Bengal) and Bangladesh is popularly known as Sundarbans. Crop productivity of the region is very poor. Agricultural lands of the region are mostly saline and low-lying with drainage congestion due to presence of brackish groundwater table at shallow depth and flat topography. In recent years, improvement in productivity of these lands was witnessed by farmers when the elevation of lowlands was increased through land shaping. In the present study changes in the salinity status of soil were due to raise of land elevation through land shaping was investigated for two years and 3 seasons (winter, summer and late summer). It was found that there was a considerable decrease in soil salinity due to increase in elevation of lowlands through land shaping. The salinity of original lowlands was about 200% higher than the raised lands or uplands made through land shaping. Salinity of rhizosphere soil decreased with depth and there was a strong seasonal variation of soil salinity. At all soil depths soil salinity increased as the dry season progressed from winter to late summer through summer and soil salinity was highest in the surface (0-10 cm). The depth to groundwater table and the groundwater salinity also showed strong seasonal variation and were maximum in late summer season. The drainage condition of soil improved with increasing in land elevation.

Open Access Original Research Article

Economic Assessment of Napier Grass Production Using Different Fertilizer Combinations under Smallholder Farming Conditions in the Central Highlands of Kenya

Bridget W. Ndwiga, Esther E. Arunga, Felix K. Ngetich

International Journal of Plant & Soil Science, Page 1-6
DOI: 10.9734/ijpss/2019/v29i530153

Aims: The objective of the study was to evaluate the cost-effectiveness of using different fertilizer combinations to improve Napier grass production within the smallholder farms.

Study Design: The experimental design was a Randomised Complete Block Design (RCBD) with three replicates per treatment. The treatments were: Di-Ammonium Phosphate (DAP); rabbit (Oryctolagus cuniculus) manure; rabbit manure plus rabbit urine; DAP plus Calcium Ammonium Nitrate (CAN); DAP plus rabbit urine; Control; and Conventional method.

Place and Duration of Study: The study was done in Embu County, Kenya from March 2015 to January 2016.

Methodology: The economic analysis to determine the most cost-effective fertilizer was done using gross margins and cost-benefit ratios approach.

Results: Rabbit manure plus urine had the highest cost of production averages at US$.154 8.13 per year at p<0.05 while the conventional method was US$ 494.59 at p<0.05. The study revealed that the most cost-effective fertilizer in Embu County was DAP plus rabbit urine treatment under ‘‘Tumbukiza’’ pits.

Conclusion: The projections are that by the end of the second cropping year, the treatment top-dressed with either rabbit urine or CAN would be having higher gross margins since the initial cost would have been recovered. Farmers in Embu County are encouraged to integrate the use of both organic and inorganic fertilizers to achieve high production in a cost-effective way.

Open Access Original Research Article

Water Use Efficiency of Maize Genotypes of Different Maturity Groups at Seedling and Grain-filling Growth Stages in a Rainforest Location

O. O. Bankole, A. Oluwaranti, F. E. Awosanmi

International Journal of Plant & Soil Science, Page 1-11
DOI: 10.9734/ijpss/2019/v29i530154

Aims: The objectives of this study were to evaluate maize genotypes of different maturity groups for seedling and grain filling water use efficiency and determine relationship that exist between the water use efficiency traits and yield of different maize maturity groups.

Study Design:  Sixteen maize genotypes were planted in Randomized Complete Block Design in three replicates for emergence, vegetative, water use efficiency traits at the seedling and grain-filling growth stages and yield.

Place and Duration of Study: The sixteen maize genotypes of different maturity groups were evaluated during the early and late cropping seasons of 2016 at the Obafemi Awolowo University Teaching and Research Farm, Ile-Ife, Nigeria

Methodology: Data collected were subjected to Analysis of Variance (ANOVA), correlation analysis among water use efficiency traits and yield for each of the maturity groups.

Results: There was no significant difference among the genotypes within each maturity groups for water use efficiency at seedling and grain filling growth stages.

The late maturity group of maize used more water at the seedling growth stage than the other maturity groups in the early season of this study while in the late season, the early and extra-early maturity groups used more water than the other maturity groups. Increase in emergence percentage, reduction in speed of germination, and minimal days to complete germination increased water use efficiency at the seedling stage only during the early cropping season.

Efficiency of water usage at the seedling growth stage was more among the late and intermediate maturing groups than the extra-early and early maturing groups in the early season while in the late season, the extra-early and early maturing groups used water more efficiently than the late and Intermediate maturing groups

Conclusion: Maturity group played a significant role in the expression and manifestation of water use efficiency traits under different environmental conditions.

Open Access Original Research Article

Morpho-physiological and Yield Responses of Sweet Potato (Ipomoea batatas (L.) Lam.) Genotypes to Frequency of Irrigation under Greenhouse Condition

Amsalu Gobena Roro, Mihret Tesfaye

International Journal of Plant & Soil Science, Page 1-17
DOI: 10.9734/ijpss/2019/v29i530155

Introduction: The sweet potato (Ipomoea batatas Lam.), is one of the root and tuber crops grown from low land to high land region of Ethiopia. However, its productivity depends on adaptability and tolerance to different environmental stresses and the capacity of the crop to enhance water use efficiency under moisture stress conditions. The objective of this study was to evaluate impact of irrigation interval on morpho-physiological characteristics of sweet potato varieties.

Methodology: The trial was a 3 x 2 factorial arrangement in CRD design consisting: three irrigation intervals (daily-control), four days and seven days interval) combined with two sweet potato genotypes (Hawassa-83 and Kulfo) with three replications.

Results: The morpho-physiological indicators, morphological traits, water use efficiency (WUE), Relative leaf water content (RLWC), leaf gas exchange, stomata density, and tuber yield were evaluated. The result indicated that morphological traits were significantly (P≤0.05) responded to genotype and irrigation frequencies. As compared to daily irrigation, an extended watering interval to seven days irrigation interval significantly reduced leaf number, vine length, branch number and internode length by 55.42, 19.83 cm, 2.17 and 0.35 cm, respectively. Stomata density was strongly responded to genotypes than effect of irrigation frequency. Genotype Hawassa-83 had approximately 2.0 more stomata per mm2 than genotype Kulfo regardless to irrigation frequency. The interaction effect between genotype and irrigation frequency revealed significant influence on photosynthesis and transpiration rate. The rate of assimilate accumulation was significantly reduced (by 9.97

Open Access Original Research Article

Influence of Organic and Inorganic Soil Amendments on Soil Moisture Content and Micronutrients

E. K. Kago, Z. M. Kinyua, J. M. Maingi, P. O. Okemo

International Journal of Plant & Soil Science, Page 1-12
DOI: 10.9734/ijpss/2019/v29i530156

Aims: This study was carried out to evaluate the influence of organic and inorganic soil amendments on soil moisture content and micronutrients in semi and arid areas.  

Methodology: The study was laid out as randomized complete block design (RCBD) in split plot arrangement for two seasons. The treatments were ChalimTM, Super-hydro-grow polymer and Metham sodium, Metham sodium, Metham sodium + Orange peel, Super-hydro-grow polymer, Control, Brassica tissue, ChalimTM + Super-hydro-grow polymer, Brassica tissue + Orange peel and Metham sodium + Super-hydro-grow polymer. Soils were sampled from each experimental site, dried and taken to laboratories for determination of Zinc, Iron, Manganese and copper both at initial and at the end of the experiment using a SpectrAA- 40 atomic absorption spectrometer, PSC-56 programmable sample changer. Moisture content was calculated by subtracting total dry soil plus Petri dish weight from total wet soil plus Petri dish weight. Calculated moisture content was recorded in all samples across the two seasons for analysis.

Results: There was a significant difference (p≤0.05) in the treatment effect on soil moisture content in except for MS and CM+OP in both season one and season two in the green house. A combination of both organic and inorganic soil amendments like BT+OP, BT+ SHG had the highest moisture content. There was significant difference (p≤0.05) in the soil amendments effect on the amount of Micronutrients in the beginning and end of the experiement.

Conclusion: Through this study, it was realized significant difference (p≤0.05) in the soil amendments effect on soil moisture content in all the treatment in both seasons. BT +SHG soil amendment was superior in maintaining soil moisture content in both season 1 and 2. It is therefore recommended that Metham sodium should not be applied in very dry soil to avoid reduction of the moisture content. There was micronutrient increment in all the treatments. BT+ SHG was superior soil amendment in increment of micronutrients.