Amending Potassic Fertilizer with Charcoal and Sago (Metroxylon sagu) Bark Ash to Improve Potassium Availability in a Tropical Acid Soil

In Ultisols and Oxisols, potassium (K) in the soil solution is leached from the rhizosphere before it interacts with soil colloids, or exchanged with other cations at the exchange sites of the soils because of the abundance of kaolinite clay minerals. These soils are highly weathered, low in organic matter, and low in pH, but high aluminium (Al) and iron (Fe) ions. Hence, K becomes unavailable for plants, and this compromises crop production and farmers’ profitability. The pH neutralizing effects of sago (Metroxylon sagu) bark ash and the ability of charcoal to chelate Al and Fe could be utilized to improve soil pH, reduce soil acidity, and improve K availability. The objective of this study was to determine the effects of amending muriate of potash (MOP) with charcoal and sago bark ash on selected soil chemical properties in a tropical acid soil (Typic Paleudults) over 90 days in a laboratory incubation. The proportions of charcoal and sago bark ash were varied at 20%, 40%, 60%, 80%, and 100%, but the MOP was fixed at 100% of the recommended rate. Selected soil chemical properties before and after incubation were determined using standard procedures. Results revealed that co-application of the soil amendments with MOP increased soil-exchangeable K compared with conventional practice. Moreover, amending the acid soil with charcoal and sago bark ash positively enhanced the availability of other base cations and soil cation exchange capacity (CEC). This was possible because the amendments increased soil pH and reduced exchangeable acidity, exchangeable Al3+, and exchangeable Fe2+. However, there was no significant improvement in water-soluble K (WSK) in the soil with or without charcoal and sago bark over the 90 days laboratory study. The findings of this study suggested that increasing soil pH could potentially improve soil K sorption capacity. Thus, the optimum rates of charcoal and sago bark ash to increase K availability were found to be 80% charcoal with 80% sago bark ash, 60% charcoal with 60% sago bark ash, and 80% charcoal with 40% sago bark ash, because these rates improved soil-exchangeable K+ and CEC significantly, besides minimizing soil-exchangeable acidity.

Download Full-text

Changes in Soil Phosphorus Pools and Chemical Properties under Liming in Nitisols of Farawocha, South Ethiopia

Applied and Environmental Soil Science ◽

10.1155/2021/5518545 ◽

2021 ◽

Vol 2021 ◽

pp. 1-11

Author(s):

Fikeremareyam Chulo ◽

Fanuel Laekemariam ◽

Alemayehu Kiflu

Keyword(s):

Soil Ph ◽

Nutrient Dynamics ◽

Soil Phosphorus ◽

Acid Soil ◽

Chemical Properties ◽

Soil Chemical Properties ◽

Southern Ethiopia ◽

Organic Part ◽

Exchangeable Acidity ◽

P Pools

Understanding the nutrient dynamics in acid soil is fundamental to carry out proper management. The study was conducted to investigate phosphorus (P) pools and selected properties under different rates of lime for acid nitisols of Farawocha, Southern Ethiopia. Four lime rates incubated for a month in three replications were tested. The lime rates were 0 t/ha (0%), 5.25 t/ha (50%), 10.5 t/ha (100%), and 15.75 t/ha (150%). Lime requirement (LR) for 100% was calculated targeting soil pH of 6.5. Data on the P pools such as soluble P (P-sol) and bounded forms of P with iron (Fe-P), aluminum (Al-P), calcium (Ca-P), organic part (Org-P), residual P (Res-P), and total of P fractions were measured. In addition, changes in soil chemical properties such as pH, exchangeable acidity, calcium (Ca), magnesium (Mg), sulfur (S), iron (Fe), copper (Cu), boron (B), zinc (Zn), and manganese (Mn) were analyzed. The result showed that total P was 357.5 mg/kg. Compared to nontreated soil, liming at a rate of 15.75 t/ha significantly improved P-sol (34.2%, r2 = 0.88), Ca-P (61.6%, r2 = 0.92), and Res-P (195%, r2 = 0.94); however, it reduced Fe-P (58.5%, r2 = −0.83), Al-P (71%, r2 = −0.97), and Org-P (19.1%, r2 = 0.93). Overall, the P-associated fractions in the soil, regardless of the lime rates, were in the order of Org_P > Res_P > Fe_P > Ca_P > Al_P > P-sol. Liming raised soil pH by 2.1 units (4.5 to 6.6) over nonlimed soil, whereas it reduced exchangeable acidity from 4.18 to 0.23 meq/100 g soil. Available P, Ca, Mg, S, Cu, Zn, and B contents were significantly improved with lime application. However, liming reduced Fe and Mn contents. In conclusion, these findings showed that liming facilitated the release of P from various pools, modified pH and exchangeable acidity, and resulted in beneficial changes for most of the soil chemical properties.

Download Full-text

The influence of Pinus radiata, Quercus suber, and improved pasture on soil chemical properties

Soil Research ◽

10.1071/s98081 ◽

1999 ◽

Vol 37 (3) ◽

pp. 509 ◽

Cited By ~ 14

Author(s):

A. D. Noble ◽

I. P. Little ◽

P. J. Randall

Keyword(s):

Soil Ph ◽

Pinus Radiata ◽

Soil Acidification ◽

Chemical Properties ◽

Radiata Pine ◽

Quercus Suber ◽

Cork Oak ◽

Water Soluble ◽

Soil Chemical Properties ◽

Permanent Pasture

Soil acidification and related land degradation issues are assuming increasing importance in Australia and challenging the concept of sustainability of current land management systems. In this study, the impacts of tree plantations of 2 species and permanent pasture on soil chemical properties are compared. Soil samples were collected from the top 50 cm (0–5, 5–10, 10–15, 15–20, 20–30, and 30–50 cm depths) from 3 adjacent sites carrying pasture and monocultures of Pinus radiata (radiata pine) and Quercus suber (cork oak) on a deep-surfaced yellow podzolic soil, and differences in soil pH and other soil chemical properties were examined. In the surface 0–5 cm, pH was similar at all 3 sites. Below that depth, soil pH was significantly lower and exchangeable Al greater under the cork oak stand than at the other 2 sites. Consistent with a decrease in soil pH there was significantly less exchangeable Ca under cork oak. Also, less clay was observed under the cork oak stand and this is taken as evidence of the degradational impact of soil acidification. An estimate of Ca in the top 50 cm of the soil implies considerable loss of Ca under oak, probably by leaching and loss of litter down the slope. Evidence is presented to show that there has been more Fe and Al movement under oak than under pasture and pine, this being ascribed in part to the greater Al and Fe mobilising capacity of the water-soluble component extracted from freshly fallen leaf litter of oak. The Fe and Al composition of the oxalate extract from concretionary material at 10–30 cm under oak is consistent with a process similar to podzolisation. Pseudogleying of Fe and Al may have accompanied the leaching of bases from the system and a reduction of pH.

Download Full-text

Optimisation of Charcoal and Sago (Metroxylon sagu) Bark Ash to Improve Phosphorus Availability in Acidic Soils

Agronomy ◽

10.3390/agronomy11091803 ◽

2021 ◽

Vol 11 (9) ◽

pp. 1803

Author(s):

Prisca Divra Johan ◽

Osumanu Haruna Ahmed ◽

Ali Maru ◽

Latifah Omar ◽

Nur Aainaa Hasbullah

Keyword(s):

Soil Ph ◽

Soil Acidity ◽

P Availability ◽

Acidic Soils ◽

Inorganic P ◽

Exchangeable Acidity ◽

P Fixation ◽

Metroxylon Sagu ◽

Sago Bark ◽

Fe Ions

Soil acidity is an important soil factor affecting crop growth and development. This ultimately limits crop productivity and the profitability of farmers. Soil acidity increases the toxicity of Al, Fe, H, and Mn. The abundance of Al and Fe ions in weathered soils has been implicated in P fixation. To date, limited research has attempted to unravel the use of charcoal with the incorporation of sago (Metroxylon sagu) bark ash to reduce P fixation. Therefore, an incubation study was conducted in the Soil Science Laboratory of Universiti Putra Malaysia Bintulu Sarawak Campus, Malaysia for 90 days to determine the optimum amounts of charcoal and sago bark ash that could be used to improve the P availability of a mineral acidic soil. Charcoal and sago bark ash rates varied by 25%, whereas Egypt rock phosphate (ERP) rate was fixed at 100% of the recommendation rate. Soil available P was determined using the Mehlich 1 method, soil total P was extracted using the aqua regia method, and inorganic P was fractionated using the sequential extraction method based on its relative solubility. Other selected soil chemical properties were determined using standard procedures. The results reveal that co-application of charcoal, regardless of rate, substantially increased soil total carbon. In addition, application of 75% sago bark ash increased soil pH and at the same time, it reduced exchangeable acidity, Al3+, and Fe2+. Additionally, amending acidic soils with both charcoal and sago bark ash positively enhanced the availability of K, Ca, Mg, and Na. Although there was no significant improvement in soil Mehlich-P with or without charcoal and sago bark ash, the application of these amendments altered inorganic P fractions in the soil. Calcium-bound phosphorus was more pronounced compared with Al-P and Fe-P for the soil with ERP, charcoal, and sago bark ash. The findings of this study suggest that as soil pH decreases, P fixation by Al and Fe can be minimised using charcoal and sago bark ash. This is because of the alkalinity of sago bark ash and the high affinity of charcoal for Al and Fe ions to impede Al and Fe hydrolysis to produce more H+. Thus, the optimum rates of charcoal and sago bark ash to increase P availability are 75% sago bark ash with 75%, 50%, and 25% charcoal because these rates significantly reduced soil exchangeable acidity, Al3+, and Fe2+.

Download Full-text

Improvement of Selected Soil Chemical Properties and Potassium Uptake by Mung Beans After Application of Liquid Organic Fertilizer in Ultisol

TERRA Journal of Land Restoration ◽

10.31186/terra.1.1.1-7 ◽

2018 ◽

Vol 1 (1) ◽

pp. 1-7

Author(s):

Tristantia Anggita ◽

Zainal Muktamar ◽

Fahrurrozi Fahrurrozi

Keyword(s):

Soil Ph ◽

Mung Bean ◽

Organic Fertilizer ◽

Chemical Properties ◽

Dry Weight ◽

Soil Chemical Properties ◽

K Uptake ◽

Exchangeable K ◽

Shoot Dry Weight ◽

Animal Wastes

Recently, application of liquid organic fertilizer (LOF) in organic farming practices is of importance to prevent further soil degradation due to prolong and massive use of synthetic fertilizer. LOF provides faster plant nutrients than soil organic fertilizer. However, quality of LOF is substantially dependent on its sources. Animal wastes from rabbit, goat, and cattle are scarcely used as sources of LOF production. The study aimed to determine soil chemical improvement and potassium uptake by mung bean as affected by LOF in Ultisol. The experiment was conducted at the Greenhouse Faculty of Agriculture, employing Completely Randomized Design with two factors. The first factor was animal wastes, consisting of goat, rabbit, and cattle wastes. The second factor was LOF concentration, consisting of 0%, 25%, 50%, 75%, and 100% LOF. LOF was prepared by mixing altogether animal feces, urine, soil, green biomass, EM-4 and fresh water to total volume of 10 l in a plastic container. LOF was decanted to the polybag every week starting at one week after planting for four weeks to a total volume of 750 ml per polybag. Variables observed included soil pH, total organic-C, exchangeable K, soil nitrate-N, K concentration in plant tissue, K-uptake, and shoot dry weight of sweet corn The result showed that application of LOF from rabbit waste had the highest increment of soil pH as compared to the other treatment. However, exchangeable K was observed highest at the treatment of LOF from goat waste. Sources of LOF from animal wastes did not have an effect on K-uptake by mung bean. In addition, application of LOF up to 100% was able to improve soil chemical properties as indicated by the increase in soil pH and exchangeable K. So did the concentration and uptake of K, as well as shoot dry weight. Fertilization with LOF has benefit to the improvement of soil chemical properties leading to better K uptake.

Download Full-text

PEMANFAATAN BIOCHAR KULIT BUAH KAKAO DAN SEKAM PADI UNTUK MENINGKATKAN PRODUKTIVITAS PADI SAWAH DI ULTISOL LAMPUNG

Jurnal Pengkajian dan Pengembangan Teknologi Pertanian ◽

10.21082/jpptp.v20n1.2017.p69-80 ◽

2017 ◽

Vol 20 (1) ◽

pp. 69 ◽

Cited By ~ 1

Author(s):

Neneng Laela Nurida ◽

Sutono , ◽

Muchtar ,

Keyword(s):

Rice Husk ◽

Soil Ph ◽

Rice Yield ◽

Acid Soil ◽

Chemical Properties ◽

Soil Chemical Properties ◽

Growth And Yield ◽

Cocoa Shell ◽

Rice Husk Biochar ◽

Planting Season

Utilization of Biochar of Cocoa Shell and Rice Husk to Increase Rice Productivity in Ultisol Lampung. Biochar application as soil amendment is technology for soil and crop productivity improvement in acid soil. The main problem of acid soil including in paddy field is high concentration of Al3+ that inhibit crops growth causing low crop production. The objective of this study was to evaluate the effects of cocoa shell and rice husk biochar on paddy field productivity and soil chemical properties. The study was conducted at Agricultural Research Station of Tamanbogo, East Lampung on June-September 2012 (planting season 1), January-April 2013 (planting season 2) and December 2013-March 2014 (planting season 3). The experimental design was split plot design, which the main plots were two types of biochar (cacao shell and rice husk), the sub plots were biochar rates 0.5 t/ha (control), 5 t/ha and 15 t/ha with five replications. The parameters measured were paddy growth, yield and soil chemical properties (soil pH,C organic, N total, available P, K total, and Al3+ ). The result showed that biochar could affect weight of rice straw and rice yield at the second and third planting season, while biochar rates could affect crop growth and yield of rice at three planting. The effect of cacao shell and rice husk biochar application with the rate of 15 t/ha could up to three planting seasons without any biochar addition in following two consecutives year, whereas addition biochar 5 t/ha was less effective. The cacao shell biochar was more effective in increasing crop growth and yield than rice husk biochar,as seen on dry grain rice yield, i.e. 3.58 t/ha (PS1) and 5.06 t/ha (PS III). During two planting seasons, both biochar at the rate of 15 t/ha were sufficient to improve soil chemical properties. Cacao shell biochar with the rate of 15 t/ha had better effect in improving soil chemical properties significantly in term of soil pH, available P, and total K content and decreasing aluminum content than rice husk biochar especially at second planting season. Keywords: lowland, biochar, rice, Ultisol, LampungABSTRAKAplikasi biochar sebagai pembenah tanah merupakan salah satu teknologi untuk memperbaiki produktivitas tanah dan tanaman pada lahan masam. Permasalahan utama pada lahan masam adalah tingginya konsentrasi Fe3+ yang dapat menghambat pertumbuhan tanaman sehingga menyebabkan rendahnya produksi. Tujuan penelitian ini adalah untuk mempelajari pengaruh pemberian biochar kulit buah kakao dan sekam padi serta takarannya terhadap peningkatan sifat kimia tanah dan produktivitas padi sawah di Ultisol Lampung. Penelitian dilaksanakan pada lahan sawah di Kebun Percobaan Taman Bogo, Lampung selama tiga musim tanam yaitu bulan Juni-September 2012 (musim tanam pertama), bulan Januari-April 2013 (musim tanam kedua) dan Desember 2013 - Maret 2014 (musim tanam ketiga). Percobaan disusun dalam rancangan kelompok petak terpisah, sebagai petak utama terdiri dari biochar kulit buah kakao dan biochar sekam padi, sedangkan sebagai anak petak adalah takaran biochar yaitu tanpa biochar (kontrol 0 t/ha), 5 t/ha dan 15 t/ha, dengan 5 kali ulangan. Parameter yang diamati meliputi pertumbuhan dan hasil padi, sifat kimia tanah (pH, C-organik, N-total, P-tersedia, K-total dan Al3+ ). Hasil penelitian menunjukkan bahwa jenis biochar hanya berpengaruh nyata terhadap berat jerami kering dan hasil gabah pada musim tanaman kedua dan ketiga, sedangkan takaran biochar berpengaruh nyata terhadap pertumbuhan dan hasil padi pada ke tiga musim tanam. Pengaruh pemberian biochar kulit buah kakao dan sekam padi 15 t/ha mampu bertahan sampai tiga musim tanam dilihat dari pertumbuhan dan hasil padi sawah, sedangkan pemberian biochar 5 t/ha bertahan satu musim saja. Efektivitas biochar kulit buah kakao dalam mendukung pertumbuhan dan hasil tanaman lebih tinggi dibandingkan sekam padi terlihat dari hasil gabah kering panen sebesar 3,58 t/ha (MT II) dan 5,06 t/ha (MT III). Selama dua musim tanam pemberian biochar kulit buah kakao sebanyak 15 t/ha juga mampu meningkatkan pH tanah, P tersedia, dan kandungan K tetapi menurunkan kandungan aluminium melebihi biochar sekam padi terutama pada musim tanam kedua.Kata kunci: produktivitas, padi sawah, biochar, Ultisol

Download Full-text

Column Study of Nitrate Downward Movement and Selected Soil Chemical Properties’ Changes in Mine Spoiled Soil as Influenced by Liquid Organic Fertilizer

10.31219/osf.io/9sngr ◽

2017 ◽

Author(s):

Zainal Muktamar ◽

Sari Hasibuan ◽

Dotti Suryati ◽

Nanik Setyowati

Keyword(s):

Soil Sample ◽

Soil Ph ◽

Organic Fertilizer ◽

Soil Column ◽

Chemical Properties ◽

Soil Chemical Properties ◽

Available P ◽

Downward Movement ◽

Exchangeable K ◽

Exchangeable Al

Open pit coal mining is common practice to extract coal from lithosphere. This system, however, will bring about soil degradation. Organic fertilization is an alternative to recover fertility of the degraded soil. The objectives of the experiment were to determine nitrate downward movement and change of selected chemical properties in the soil column and to compare the growth of lamtoro (Leucaena leucocephala) as affected by local based liquid organic fertilizer. Column experiment was conducted using mine spoiled soil from Taba Penanjung Sub-District, Central of Bengkulu District, Bengkulu, Indonesia located at approximately 364.5 m above sea level. The experimental design was Completely Randomized Design with 3 treatments consisting of control, 75 and 150 ppm of local based liquid organic fertilizer (LOF). The treatment was replicated 3 times. Soil column was prepared using PVC pipe with diameter of 12.5 cm and length of 40 cm. Soil sample was put into the column and compacted by knocking the base of the column until the soil height achieved 35 cm. Lamtoro was raised in the column for 11 weeks. At the end of experiment, lamtoro shoot was cut and the PVC column was cleaved horizontally and soil was pushed out from the column. Soil sample was, then, sliced into 6 fractions, representing depth of 0-5, 5-10, 10-15, 15-20, 20-25, and > 25 cm. Fresh soil sample from each depth was extracted by distillated water and analyzed for NO3- N. Remaining of soil samples was air-dried for 72 hours, grinded with 0.5 mm screen, and analyzed for available P, exchangeable K, soil pH and exchangeable Al. The experiment indicated that local based liquid fertilizer significantly increased soil NO3-N, available P, exchangeable K, soil pH and reduced exchangeable Al. Higher rates of LOF caused increase in selected soil chemical properties but exchangeable Al. However, NO3-N was potential to move downward to deeper depth of the soil profile. Change of exchangeable Al, soil pH and exchangeable K was observed until 20-25 m depth of soil profile, but change of available P was detected only to 10-15 cm depth. Better soil chemical properties were followed by enhancement of lamtoro growth.

Download Full-text

Coapplication of Chicken Litter Biochar and Urea Only to Improve Nutrients Use Efficiency and Yield ofOryza sativaL. Cultivation on a Tropical Acid Soil

The Scientific World JOURNAL ◽

10.1155/2015/943853 ◽

2015 ◽

Vol 2015 ◽

pp. 1-12 ◽

Cited By ~ 6

Author(s):

Ali Maru ◽

Osumanu Ahmed Haruna ◽

Walter Charles Primus

Keyword(s):

Acid Soil ◽

Nutrient Use Efficiency ◽

Chemical Properties ◽

Acid Soils ◽

Field Trials ◽

Soil Chemical Properties ◽

Nutrient Use ◽

Chicken Litter ◽

Rice Yields ◽

Use Efficiency

The excessive use of nitrogen (N) fertilizers in sustaining high rice yields due to N dynamics in tropical acid soils not only is economically unsustainable but also causes environmental pollution. The objective of this study was to coapply biochar and urea to improve soil chemical properties and productivity of rice. Biochar (5 t ha−1) and different rates of urea (100%, 75%, 50%, 25%, and 0% of recommended N application) were evaluated in both pot and field trials. Selected soil chemical properties, rice plants growth variables, nutrient use efficiency, and yield were determined using standard procedures. Coapplication of biochar with 100% and 75% urea recommendation rates significantly increased nutrients availability (especially P and K) and their use efficiency in both pot and field trials. These treatments also significantly increased rice growth variables and grain yield. Coapplication of biochar and urea application at 75% of the recommended rate can be used to improve soil chemical properties and productivity and reduce urea use by 25%.

Download Full-text

Liming Effects of Sawdust Ash and Lime on Sunflower (Helianthus annuus L.) Yield in Acidic Soil of Southeastern Nigeria

International Journal of Plant & Soil Science ◽

10.9734/ijpss/2019/v28i530121 ◽

2019 ◽

pp. 1-11

Author(s):

C. V. Ogbenna ◽

V. E. Osodeke

Keyword(s):

Soil Ph ◽

Chemical Properties ◽

Exchange Capacity ◽

Acidic Soil ◽

Soil Chemical Properties ◽

Growth And Yield ◽

Available Phosphorus ◽

Yield Data ◽

Southeastern Nigeria ◽

Head Weight

Aim: A pot experiment was carried out to determine the effect of sawdust ash and lime (Ca(OH)2) on soil characteristics and yield of sunflower in acidic soil of southeastern Nigeria. Study Design: The experiment was laid out in split-plot design, using sawdust ash (0, 1, 2, 3, 4 t ha-1) as the sub plot and lime (0, 0.5, 1.0, 1.5 t ha-1) as the main plot. Place and Duration of Study: Study was conducted outdoors at Michael Okpara University of Agriculture Umudike, Nigeria, during the 2010 planting season. Materials and Methods: Treatment combinations were applied to the 60 buckets containing soil, mixed thoroughly and watered adequately. After 1 week of treatment application, two sunflower seeds were planted and later thinned to one seedling per bucket. Plant growth and yield data were collected. Pre planting and post-harvest soil samples were collected and analyzed for soil properties. Results: Results showed that with the exception of organic carbon there was significant effect of treatments on all soil chemical properties. Lime and sawdust ash (SDA) as single and combined treatments significantly increased total nitrogen (P=0.05), available phosphorus (P<0.010), and base saturation (P<0.012). The interaction between SDA and lime significantly (P=0.05) increased total exchangeable bases and effective cation exchange capacity, while soil pH was significantly increased (P=0.05) by single applications. The increases in soil chemical properties led to significant positive response of the sunflower. With the exception of number of leaves, other plant parameters (Plant height, stem diameter, head weight, 50 seed weight, head diameter) had significant increases for sawdust ash alone at P=0.05. Correlation studies showed positive significant relationship between soil pH and sunflower yield. Conclusion: The study showed that sunflower performed best at the combination of 3 tha-1 SDA and 1.5 t ha-1 lime producing a mean head weight of 45.4 g.

Download Full-text

Vertical distribution of soil nutrients under different land use systems in Bangladesh

Journal of Aridland Agriculture ◽

10.25081/jaa.2020.v6.6438 ◽

2020 ◽

pp. 6-12

Author(s):

Tahsina Sharmin Hoque ◽

Shafia Afrin ◽

Israt Jahan ◽

Md. Joinul Abedin Mian ◽

Mohammad Anwar Hossain

Keyword(s):

Electrical Conductivity ◽

Land Use ◽

Organic Matter ◽

Soil Ph ◽

Soil Depth ◽

Organic Matter Content ◽

Soil Samples ◽

Water Soluble ◽

Exchangeable K ◽

Land Use Systems

Soil depth can significantly influence the availability of nutrients in soil. An experiment was conducted with seven soil samples from seven land use types to observe the effect of soil depth on soil properties under various land use systems. Soil pH, electrical conductivity (EC), organic matter, available phosphorus (P), available sulphur (S) and different forms of potassium (K) such as water soluble, exchangeable and non-exchangeable were determined from the soil samples collected from four soil depths (viz. 0-10, 10-20, 20-30 and 30-40 cm). Soil pH varied from 6.30-7.39 irrespective of depths and land uses and it increased with increasing soil depth. Electrical conductivity of the soils ranged from 42-310 µS cm-1 and organic matter status of most of the soils was very low to medium in level. Both EC and organic matter content decreased with the increase of soil depth. Available P concentration showed no specific changing trend with soil depth whereas available S concentration under different land use systems decreased with increasing soil depth. The concentrations of water soluble, exchangeable and non-exchangeable K in soils varied from 12.30-39.60, 20.90-53.16 and 163.30-684.30 mg kg-1, respectively and showed no specific changing pattern with soil depth. Water soluble K content was higher in rice growing fertilizer and manure-treated soil but higher exchangeable and non-exchangeable K contents were observed in banana growing soil. In rice growing soils, nutrient concentration is mostly higher in nitrogen (N), P and K + farm yard manure (FYM) - treated plots compared to rice growing control plots.

Download Full-text

Effects of biochars generated from crop residues on chemical properties of acid soils from tropical and subtropical China

Soil Research ◽

10.1071/sr12118 ◽

2012 ◽

Vol 50 (7) ◽

pp. 570 ◽

Cited By ~ 51

Author(s):

Jin-Hua Yuan ◽

Ren-Kou Xu

Keyword(s):

Soil Ph ◽

Crop Residues ◽

Chemical Properties ◽

Acid Soils ◽

Base Cations ◽

Exchange Capacity ◽

Chemical Compositions ◽

Subtropical China ◽

Exchangeable Base Cations ◽

Exchangeable Acidity

The chemical compositions of biochars from ten crop residues generated at 350°C and their effects on chemical properties of acid soils from tropical and subtropical China were investigated. There was greater alkalinity and contents of base cations in the biochars from legume residues than from non-legume residues. Carbonates and organic anions of carboxyl and phenolic groups were the main forms of alkalis in the biochars, and their relative contributions to biochar alkalinity varied with crop residues. Incubation experiments indicated that biochar incorporation increased soil pH and soil exchangeable base cations and decreased soil exchangeable acidity. There were greater increases in soil pH and soil exchangeable base cations, and a greater decrease in soil exchangeable acidity, for biochars from legume than from non-legume residues. The biochars did not increase the cation exchange capacity (CEC) of soils with relatively high initial CEC but did increase the CEC of soils with relatively low initial CEC at an addition level of 1%. The incorporation of biochars from crop residues not only corrected soil acidity but also increased contents of potassium, magnesium, and calcium in these acid soils from tropical and subtropical regions and thus improved soil fertility.

Download Full-text