EURASIAN JOURNAL OF SOIL SCIENCE

1 - 10

Authors: Siti Wardah Zaidun , Mohamadu Boyie Jalloh , Azwan Awang , Lum Mok Sam , Normah Awang Besar , Baba Musta , Osumanu Haruna Ahmed , Latifah Omar

Increase in cost of chemical fertilizers encourages the use of soil amendments such as biochar and zeolites to improve soil fertility. In this study, biochar produced from empty fruit bunch-palm oil mill effluent (EFB-POME) and clinoptilolite zeolite were used as soil amendments to improve soil fertility. The field experiment was carried out for two planting cycles to determine the effects of different rates of EFB POME biochar (0, 10, and 20 t ha-1), clinoptilolite zeolite (0, 1.25, and 2.5 t ha-1), and urea (60 and 120 kg ha-1) on selected soil chemical properties of Tanjung Lipat (Typic Paleudults). Biochar produced from EFB-POME increase soil total N, P, K, Ca, and Mg. The higher soil total N, P, K, Ca, and Mg could be related to the increase in soil pH, cation exchange capacity, and total organic carbon in soil with EFB-POME biochar but not with clinoptilolite zeolite. Thus, EFB-POME biochar was more suitable to be used in a tropical soil (Typic Paleudults) compared to clinoptilolite zeolite for improving the selected soil pH, CEC, TOC and available P, K, Ca and Mg.

17 - 26

Authors: Muhammad Irfan , Muhammad Abbas , Javaid Ahmed Shah , Nizamuddin Depar , Muhammad Yousuf Memon , Niaz Ali Sial

Most of the arable soils in Pakistan are deficient in plant available phosphorus (P) and boron (B) primarily due to alkaline and calcareous nature along with low organic matter. A combined deficiency of these nutrients may intensify the plant growth suppression by reducing their efficient utilization. A pot experiment was conducted to investigate the interactive effect of P and B on growth, nutrient accumulation and grain yield of wheat grown on calcareous soil. Wheat crop was grown at three P levels (45, 90 and 135 kg P ha-1) in combination with five B levels (0, 0.5, 1.0, 1.5 and 2.0 kg B ha-1) following completely randomized design. The results revealed that yield and yield related attributes increased linearly with the addition of B at each P level. Nonetheless, the significant interactive effect of both nutrients was most pronounced in the treatment having 90 kg P ha-1 and 1.5 kg B ha-1. Applied B rates resulted in relatively higher P concentration in grains and straw at P level of 90 kg ha-1 contrarily to 45 and 135 kg P ha-1. The B concentration in grains and straw increased with corresponding addition of B at each P level but at variable rate, with the maximum response at higher P level. Grain and straw yield illustrated positive correlation with total P uptake (R2 = 0.96 and 0.81) and total B uptake (R2 = 0.95 and 0.70) respectively. Likewise, positive correlation (R2 = 0.94) between total P uptake and total B uptake under combined application of P and B indicated their synergistic relationship. Overall, the treatment combination of 90 kg P ha-1 with 1.5 kg B ha-1 was found as the most suitable dose for better plant growth, nutrient accumulation and grain yield of wheat.

35 - 43

Authors: Orhan Dengiz , Fikret Saygın , Ali İmamoğlu

The main objectives of the current study are i) to estimate SOC in different soil depths and to generate their spatial distribution maps, ii) to assess relationship between variation of different soil types and SOC density, iii) to determine effects of land cover types on SOC in Inebolu Watershed located in sub-humid terrestrial ecosystem. In order to determine land cover types of the study area, aster satellite image was used and five main land cover types that are bare land, sparsely vegetated area, broadleaved forest area, mixed forest area and needleleaved forest area were classified. Results indicated that soil types and land cover were two crucial influencing factors for spatial variation of SOC density. It was determined that SOC density of soil types, Vertic Haplustept (12.93 kg.m-2) was significantly higher than other soil subgroups. In this case, it can be said that main reasons of this result are indicated as soil profile depth and pedological development. In addition, when comparing the two main factors, land cover explained more of the SOC density variability and was the main controlling factor in the surface; in the subsurface, not only land cover types but also some properties of soil types such as texture, genetic horizons, soil depth have an important role on SOC density. On the other hand, it can be conclude that the combination of the soil type and land cover was a dramatically better predictor of SOC density.

54 - 59

Authors: Taiki Mori , Ryota Aoyagi

We aimed to test if anthropogenic P input into ecosystems reduces microbial resource allocation to acquire N (and alleviate N shortage if any) because microbes no longer produce N-rich phosphatase for P acquisition. Literatures reporting the effect of P fertilization on C-acquiring (β-1,4-glucosidase, BG) and N-acquiring (β-1,4-N-acetylglucosaminidase, NAG, which also acquires C) enzymes were collected and synthesized. We predicted that P addition elevates BG:NAG especially in P-poor ecosystems because P addition alleviates N shortage and reduces the microbial resource allocation to acquire N relative to C. The synthesized data demonstrated that P fertilization occasionally reduced BG:NAG, which is inconsistent with the prediction. However, this might not mean that the initial hypothesis was rejected. Stimulated microbial activity and turnover by P fertilization could have caused microbes depend the C sources more on chitin (and peptidoglycan) compared with on cellulose because chitin (and peptidoglycan) is a main component of microbial body and re-provided through microbial turnover. The changes in C resources accompanied by the altered P availability may have largely influenced BG:NAG, masking the role of BG:NAG for indicating microbial resource allocation to C and N acquisitions.

73 - 82

Authors: Julius Romiluyi Orimoloye , Oluwatosin Abimbola Egbinola

A study was carried out to evaluate the suitability of some Peri-urban soils in Lagos state for arable crop production. Six pedons classified as Alagba (Rhodic Hapludult), Dodokindo (Plinthic Kandiudult), Idesan (Typic Endoaquept), Owode (Typic Kandiudult), Atan (Fluvaquentic Endoaquept) and Pakoto (Plinthic Kandiudult) Series identified at two study sites located at Igbokuta and Ibomwon communities in Ikorodu and Epe Local Government Areas of Lagos state were evaluated. The land use potentials for maize, cassava and leafy vegetables (Amaranth family) were assessed following the conventional non-parametric and the parametric (square root) methods of land suitability evaluation according to the revised FAO framework. All the pedons were rated as marginally suitable (S3) for maize except Idesan and Owode Series that made up 2.53% and 34.74% of the total area respectively, which were rated moderately suitable (S2). With respect to cassava and leafy vegetables, all the pedons were rated marginally suitable (S3) except Atan Series occupying 19.71 % of the total area, that was rated non-suitable (N1). The major limitations to sustainable crop production in all pedons were low nutrient supply (N, K, P and cations) coupled with high soil acidity (pH of between 3.9 and 5.8). In addition to this, Idesan and Atan series also have waterlogging problem hence may not be used for cultivating the afore-mentioned crops, but could be used for swamp rice. With appropriate liming, soil fertility management and proper drainage, most of the pedons may be rated as being moderately suitable (S2) for the cultivation of these crops. As a peri-urban area with high demand for agricultural products, year-round cropping with irrigation facilities is quite promising in most of the pedons studied.