Open Access Original Research Article

Regression of Grain Yield of Maize Inbred Lines and Their Diallel Crosses on Elevated Levels of Soil-Nitrogen

A. M. M. Al-Naggar, R. Shabana, M. M. M. Atta, T. H. Al-Khalil Al-Khalil

International Journal of Plant & Soil Science, Page 499-512
DOI: 10.9734/IJPSS/2015/14228

Maize grain yield response to elevated levels of soil nitrogen is dependent upon genotype of the cultivar. Thus the optimum rate of N-fertilizer differs from maize genotype to another according to its nitrogen use efficiency (NUE). The main objective of this study was to determine the optimum N-rate for each studied inbred and hybrid that maximize grain yield. Six inbred lines of maize differing in their productivity under low-N were crossed in a diallel fashion to produce 15 F1ËŠs. Parents and F1ËŠs were evaluated in two seasons (2012 and 2013) using a split-plot design in randomized complete blocks arrangement with 3 replications. Main plots were allotted to four N-rates, i.e. 0, 80, 160 and 240 kg N/fed for N1, N2, N3 and N4, respectively. The sub-plots were assigned for the genotypes. Reducing N-level from 204 to 160, 80 and 0 kg N/feddan (fed) [one fed = 4200 m2] caused an increase in days to silking (DTS), anthesis silking interval (ASI), barren stalks (BS), economic NUEe and biological NUEb NUE and a decrease in the remaining studied traits including grain yield and its component. Maximum increase and decrease in traits occurred at N1 level (0 kg N/fed). The inbred lines L17, L18 and L53 proved to be tolerant (T), while L29, L54 and L55 inbred lines were sensitive (S) to N stress. The most tolerant crosses to low-N stress and the most responsive crosses to elevated levels of nitrogen were identified. Only two crosses (L18 × L53 and L18 × L55) showed high tolerance to low-N stress and responsiveness to high-N expressed in grain yield per plant (GYPP) and per fed (GYPF). The T×T group of crosses exhibited better performance in most studied traits than T×S and S×S groups of crosses under the low and high N levels. The three inbred lines L53, L18 and L17 and the three groups of crosses [inefficient responsive (IR), efficient non-responsive (ENR) and inefficient non-responsive (INR)] showed a quadratic response to the elevated levels of nitrogen with an optimum N level of 180 kg N/fed, while the three inbred lines L54, L29 and L55 and the efficient responsive (ER) group of crosses (L18 × L53 and L18 × L55) showed near linear response to elevated N levels.

Open Access Original Research Article

Nutrient Release Pattern of Cocoa Pod Husk Based Composts in an Incubation Study

C. O. Kayode, O. E. Ayanfe Oluwa, A.F. Adekunle, D. O. Ogunleti, D. T. Ezekiel-Adewoyin

International Journal of Plant & Soil Science, Page 513-520
DOI: 10.9734//IJPSS/2015/10609

In order to apply compost to fulfill the nutrient requirements of a crop, knowledge of the amount of nutrients mineralized following application is needed. The objective of this study was to compare the effect of different cocoa pod husk based composts on soil nutrient status as well as the pH. The experimental design was 4 x 2 x 5 factorial laid in a completely randomized design replicated three times. The factors were four compost types; Cocoa Pod Husk + Poultry Manure + Neem leaves (CPH + PM + NL), Cocoa Pod Husk + Poultry manure (CPH + PM), Cocoa Pod Husk + Neem leaves (CPH + NL) and No compost (Control), two soil types; Ibadan (Alfisol) and Ikenne (Ultisol) and five incubation periods; 2, 4, 6, 8 and 10 weeks. Each compost was applied separately at the rate of 10 tons ha-1. Routine analysis of the soil before incubation indicated that the two soil types had low nutrient status. The composts significantly (p<0.05) influenced the soil nutrient status after incubation. Correlation of nutrient release with time by composts showed that there was no correlation between the time of incubation and nutrient release from all the composts except in the case of CPH + PM that had significant relationship with the release of N. The result showed that the N release from CPH+PM decreases with time of incubation. The pH of the soils treated with different composts was significantly increased compared with control.

Open Access Original Research Article

Reaction Classes and Phosphorus and Potassium Contents of Soils in Major Potato Growing Areas of West Shoa Zone as Determined through Different Methods

Tesfaye Balemi, Ibrahim Hamza, Abate Bayeh

International Journal of Plant & Soil Science, Page 521-534
DOI: 10.9734/IJPSS/2015/13405

Poor soil fertility management has been one of the major factors constraining potato productivity on farmers’ field in Ethiopia, creating a wide gap between the actual yield and potential yield. A study was conducted in West Shoa Zone, Ethiopia to investigate the reaction classes as well as phosphorus and potassium contents of soils of farmers managed potato farms. Soil samples, from a depth of 0-30 cm, were collected from six districts during the Belg (March-June) cropping season to determine pH, phosphorus and potassium contents. Soil pH was determined using both water and 0.01 M calcium chloride solutions. Available phosphorus content in the soil was determined using both CAL and Olsen methods. Potassium content of the soil was determined both by extracting the potassium with Calcium Acetate Lactate (CAL) solution as well as by 1 M ammonium acetate solution. Results showed that the soil pH in all the districts was generally low, the average soil pH determined in CaCl2 suspension ranged between 4.9-5.5. Most of the fields sampled in Chelia, Welmera, Ejere, Tikur-Inchini and Jibat districts had low and very low CAL-P value while all the fields sampled in Jeldu district had CAL-P only in the target, high and very high classes. 58.5% of the sampled fields had a CAL-K value in the very high class and above. 56% of the sampled fields had an ammonium acetate extractable K content in a class ranging from moderately high to very high. Nearly 70% of the fields had low, very low and extremely low according to Olsen P test. Only 9.5% of the surveyed field soil was rated as having low or very low Olsen P while 80.5% had K content of target value and above.

Open Access Original Research Article

Basil (Ocimum basilicum L.) Water Use, Crop Coefficients and SIMDualKc Model Implementing in a Semi-arid Climate

Houshang Ghamarnia, Davod Amirkhani, Issa Arji

International Journal of Plant & Soil Science, Page 535-547
DOI: 10.9734/IJPSS/2015/14098

The accurate estimation on crop evapotranspiration (ETc) and crop coefficients is of assistance infield proper irrigation and water management. In present study, experiments were carried through out two years (i.e., 2012 and 2013) to determine water requirements (single and dual crop coefficients of basil) by using a few drainable lysimeters in a semi-arid region in Iran. Three lysimeters were used for grass evapotranspiration while three others were used to estimate bare soil evapotranspiration. Also, basil seeds were planted in six lysimeters and two groups, including group A where plant grew continually until the end of flowering stage, and group B where the plant was harvested three times after it reached a height of 0.25-0.30 m. The average water requirements of basil in two lysimeters including groups A and B were determined to be 636.8and 849mm, respectively. Finally, single and base crop coefficients for lysimeters in group A for the initial development and middle stages of basil growth were determined to be as 0.71, 1.11, 1.39and 0.57, 0.97, 1.26, respectively. Moreover, SIMDualKc, a soil water balance and irrigation scheduling model, was developed by using dual crop coefficient approach for ETc estimation. The model was calibrated and validated by comparing the measured and simulated Dual Kc values for basil for a semi-arid climate. The results indicated with low RMSE and MBE and highR2=0.83,the model was capable of accurate in proper irrigation, planning and scheduling in semi-arid climates.

Open Access Original Research Article

Partial Replacement of the Mineral Nitrogen Fertilizers by Organic Alternatives in Sandy Soils

R. T. Rashad, K. A. Shaban, R. A. Hussien

International Journal of Plant & Soil Science, Page 548-559
DOI: 10.9734/IJPSS/2015/13065

Aims: A field experiment had been carried out to study the effect of partial substitution of the mineral nitrogen (N) fertilization by using the compost on the peanut productivity in sandy soil.
Study Design: Each experiment was carried out in a complete randomized block. Twelve treatments resulting from the factorial treatment structure of two factors: compost with 3 rates (0, 11.90 and 23.81 Mg ha-1) plowed 25 days before peanut lines planting and mineral N with 4 rates (0, 119.05, 178.57 and 238.1 kg N ha-1) after 21, 40 and 55 days of peanut planting applied in the form of ammonium nitrate (33% N).
Place and Duration of Study: During the two successive summer seasons 2012 and 2013.
Methodology: Seeds of peanut were sown and fertilization practices were performed as recommended. Soil and plant analysis had been carried out according to references. Data were calculated, analyzed and fertilizers use efficiency indices were calculated.
Results: It was found that the combination between both sources of N fertilizers has increased the soil available nutrients; NPK, Zn, Mn, and Fe, the peanut seeds yield and weight of pods yield as the fertilization rates increase compared with the non-fertilized control samples. The seeds yield had increased by 178.04%, 257.26% and 373.14% while the oil content of seeds increased by 1.55%, 1.63%, 8.69% for the compost/0 – mineral treatment, mineral/0 – compost treatment and the compost/mineral treatment, respectively. The seeds content of NPK, protein and total carbohydrates for the mentioned treatments had also increased.
Conclusion: The numerical values of the N use efficiency indices of the organic compost were greater than those for the mineral fertilizer indicating the greater fertilizing effect of the former than the later. But high rates of a mineral fertilizer in presence of an organic one may diminish many of the N use efficiency indices due to loss by leaching or consuming in the microbial activity of OM.

Open Access Original Research Article

Effect of Combined Application of NPK Fertilizer and Poultry Manure on the Nutritional and Functional Properties of Aerial Yam (Dioscorea bulbifera)

V. C. Ezeocha, N. R. Njoku, A. E. Ogbuagu, L. I. Chukwu, O. N. Eke-Okoro

International Journal of Plant & Soil Science, Page 560-566
DOI: 10.9734/IJPSS/2015/14208

Aims: To investigate the effects of combined application of NPK fertilizer and poultry manure on the nutrient composition and functional properties of flours from aerial yam (Dioscorea bulbifera).
Study Design: The experiment was a single factor trial in a randomized complete block design replicated three times.
Place and Duration of Study: National Root Crops Research Institute, Umudike Research farm in 2012 and 2013 cropping seasons.
Methodology: The treatment combinations consisted of four levels (150, 250, 350 and 450kg/ha) of NPK 15:15:15 fertilizer and four levels (1, 2, 3, 4t/ha) of poultry manure with a control (No fertilizer or manure application). After harvest the bulbils were analysed for starch yield, proximate composition (dry matter, crude protein, ash, crude fibre, crude fat), total carotenoid and mineral (phosphorus, calcium and magnesium) contents. The functional properties of the flour were also investigated.
Results: Starch content increased significantly from 8.52% in the control to 14.95% in 450:1 NPK and poultry manure, ash content increased from 3.73% in control to 6.58% in 350:1 and 450:1 NPK and poultry manure. Crude protein increased from 1.35% in control to 4.33% in 350:2NPK and poultry manure. However the dry matter content decreased from 31.06% in the control to 22.28% in 250:1 NPK and poultry manure. Gelatinization temperature increased from 74ºC in the control to 88.50ºC in 450:2 NPK and poultry manure. Bulk density was not significantly affected by NPK and poultry manure, however, swelling index reduced from 200.16 in the control to 80.50 in 350:4 NPK and poultry manure.
Conclusion: Combined application of NPK and poultry manure may increase some nutrients in Dioscorea bulbifera however some important functional properties of the flours were adversely affected which may have effect on its utilization.