EURASIAN JOURNAL OF SOIL SCIENCE

9-16

Authors: Md. Zulfiker Ali , Mohammad Saiful Alam , GKM Mustafizur Rahman , Md. Mizanur Rahman , Md. Moshiul Islam , Md. Ziauddin Kamal , Md. Shahadat Hossain

The study was conducted at the experimental field of the Department of Soil Science of Bangabandhu Sheikh Mujibur Rahman Agricultural University (BSMRAU), Gazipur, Bangladesh during July to November 2015 in transplanted aman (T. aman) season to evaluate the influence of rice straw application on growth and yield of rice (BINA dhan7) and soil fertility. The experimentation was established following a randomized complete block design (RCBD) using 3 treatments (T1= Inorganic fertilizer dose as per STB, T2= rice straw + inorganic fertilizer as IPNS basis and T3= Farmer’s practice). Results of the experiment showed that application of rice straw along with inorganic fertilizers as IPNS basis did not produce any significant (p<0.05) variation in yield and yield regulating parameters of T. aman rice but ensured higher filled grains panicle-1 (96.68), 1000- grain weight (23.23g), straw (6.97 t/ha) and grain yield (6.32 t/ha) as compared to other treatments. Short term addition of rice straw in soil did not create any significant influence on post harvest soil nutrient status except K which was found high. Significantly highest N contents in grain and straw were observed in straw added plots, which further contributed to higher nutrient uptake by grain and straw.

26-31

Authors: Shahab Ahmad Khosa , Kehinde O. Ernile , Khalid Saifullah Khan , Muhammad Akmal

Phosphorus deficient soil was amended with compost (C) (organic source of phosphorus) and inorganic P (KH2PO4 as inorganic phosphorus) at different rates and incubated for 28 days. Six treatments were used including i) Control ii) Inorganic P (0.79 mg per 30 g of soil sample) iii) 100 % C (0.13 g) iv) 75% C (0.1 g) + 25% P (0.2 mg) v) 50% C (0.065 g) + 50% P (0.4 mg) vi) 25% C (0.03 g) + 75% P (0.6 mg). Soil respiration was recorded using Infra-red CO2 gas analyzer. MBC was determined by using fumigation extraction method. Resin P and MBP extraction was carried out by anion exchange membranes and was determined colorimetrically. P pools were determined by using DeLuca method. Cumulative respiration microbial biomass significantly increased in organic amended soil with higher increase in soil emended with 75% C +25% P rate followed by 50% C and 50% P rate. It was concluded that compost amended with high inorganic P stimulated the formation of P labile pools which supply long term slow release of P for plants and microbes.

38-50

Authors: Rıdvan Kızılkaya , Zhainagul Yertayeva , Sagynbay Kaldybayev , Bolat Murzabayev , Aigul Zhapparova , Zhanybek Nurseitov

Vermicomposting of organic waste has an important part to play in an integrated waste management strategy. The aim of the present study was to investigate the ability of an epigeic earthworm Eisenia foetida to transform anaerobically digested sewage sludge (SS) amended with hazelnut husk (HH) and cow manure (CM) in different proportions under laboratory condition (in darkness at 25°C0,5 0C). Two approaches investigated in the study were: (1) to find the best medium for growth and reproduction of E. foetida in different feed mixtures, (2) to analyze the heavy metal concentrations in different feed mixtures of SS-HH-CM before and after vermicomposting, and (3) to explore heavy metals accumulation of earthworms in sewage sludge with different feed mixtures. Number and biomass of earthworms and heavy metal contents in feed mixtures and earthworms were periodically monitored. The results indicated that maximum earthworm biomass was attained in feed mixture of 20% SS + 40% CM + 40% HH while the earthworm number was highest in feed mixture of 30% SS + 35% CM + 35% HH during the vermicomposting period. Heavy metals concentration (Zn, Cu, Cd, Pb, Ni and Cr) in all feed mixtures decreased associated with the increasing vermicomposting time. The heavy metals’ content in the feed mixtures was lower than that of initial mixtures. Metal analysis of earthworms revealed considerable bioaccumulation of heavy metals in their bodies’ tissue. Heavy metal analysis of earthworm body showed that increasing proportion of SS in the feed mixtures promoted the heavy metal content of earthworm body.

61-68

Authors: Vasanthakumari Roshni , Variampally Sankar Harikumar

Fluoride contamination has now become an emerging concern in agroecosystems. A diagnostic survey was conducted across the fluoride (F-) contaminated wetlands of Kuttanad, India with an aim to examine the influence of edaphic factors on F- concentration in soils. The soils (Inceptisols) predominantly sandy had a substantial percentage of clay and the soil characteristics such as bulk density (BD), moisture, temperature, pH, electrical conductivity (EC), cation exchange capacity (CEC) and organic carbon (OC) varied with soils. Similarly, the soil nutrients (NPK) and the oxides of Fe and Al as well as total sesquioxide differed with soils. Principal component analysis (PCA) revealed that the first two components (PC1 and PC2) significantly explained the variability existed in the data while the third component (PC3) did not explain any variation compared to the first two components. PC1, PC2 and PC3 accounted for 52.2%, 12.7% and 11.3% of the variation in the profiles respectively. Out of soil samples, 53% had a similar distribution of soil characteristics and F- concentration and are grouped together in PC1 while, the remaining 47% of the samples had a similar distribution of characteristics and are grouped together in PC2. Among the soil characteristics examined, silt content, pH, EC, CEC, OC, N and P had a significant (P<0.001) positive association along PC1 indicating that these factors are contributing to the augmentation of F- concentration in the wetlands of Kuttanad.

77-86

Authors: Christianah Olubunmi Kayode , Gideon Olajiire Adeoye

Dry matter yield of okra with cocoa pod husk-based (CPH) compost was assessed in a pot experiment. Three CPH-based composts: CPH+Neem leaf (CPH+NL), CPH+Poultry manure (CPH+PM) and CPH+PM+NL at the rate of 25, 50, 75, 100 kg N ha-1 each and NPK fertilizer at 40, 50, 60 kg N ha-1 and control, were applied to 5 kg soil each with three replicates and arranged in a completely randomized design. Two varieties of okra (NH47-4 and LD88) were grown. Plant height, stem girth and number of leaves were measured at 6 weeks after sowing while dry matter yield (DMY) and nutrient uptake were determined. Pre- and post- cropping soil analyses were done. Data were analyzed using ANOVA and means separated by DMRT at α = 0.05. DMY for NH47-4 ranged from 6.5g (control) to 16.7g (NPK 60 kg N ha-1) and from 5.1g (control) to 7.5g (CPH+NL 100 kg N ha-1) while LD88 ranged from 8.3 g (control) to 19.1g (CPH+PM 75 kg N ha-1) and 4.0g (control) to 9.6g (CPH+PM75 kgNha-1 ) in main and residual planting respectively. The N, P and K uptake of NH47-4 and LD88 were significantly enhanced with fertilizer treatments compared to the control. After the residual planting, pH of soil ranged from 6.2 (control) to 7.0 (CPH+NL 50 kg N ha-1) with NH47-4 and 6.3 (control) to 6.9 (CPH+PM+NL 50 kg N ha-1) with LD88. Organic carbon ranged from 9.7 gkg-1 (control) to 22.7 gkg-1 (CPH+PM+NL 50 kg N ha-1) with NH47-4 and 13.9 gkg-1 (control) to 20.3 gkg-1 (CPH+PM+NL 50 kg N ha-1) with LD88. Total N ranged from 0.1 gkg-1 (control) to 0.8 gkg-1 (CPH+PM+NL 100 kg N ha-1) with NH47-4 and 0.1 gkg-1 (control) to 0.7 gkg-1 (CPH+PM+NL 75 kg N ha-1) with LD88. The P, Ca, Mg and Na were significantly increased with fertilizer compared to control. It could therefore be concluded that CPH-based compost could be a good fertilizer for okra growth and soil fertility improvement.