Dolomite Dose Research Articles

Impact of Dolomite Liming on Ammonia-Oxidizing Microbial Populations and Soil Biochemistry in Acidic Rice Paddy Soils

Background and Aims: Over the last few decades, rampant nitrogen fertilization has exacerbated soil acidification in agricultural ecosystems. To counteract this, liming has become an essential technique for rehabilitating fertility in acid-degraded agricultural soils. Our research aimed to shed light on the response of ammonia oxidizers to liming in acidic soils within a controlled rice paddy experiment. We conducted a pot experiment with rice, featuring three different treatments: a control with only soil, a low dolomite dose (LD), and a high dolomite dose (HD). Various soil properties were investigated throughout the study. Under flooding, soil pH values rose across the treatments, from 5.4 in the control to 6.8 in HD. Ammonium and nitrate levels peaked in the HD treatment, reaching 30 and 22 mg kg−1, respectively. Similarly, dissolved organic carbon and microbial biomass carbon surged at mid-season aeration, hitting highs of 101 and 30 mg kg−1, respectively, in the HD treatment. Ammonia-oxidizing bacteria (AOB) and archaea (AOA) were responsive to dolomite-lime application, with distinct reactions; AOB abundance and potential nitrification rates were positively affected by higher lime doses, whereas AOA numbers decreased over time and with dolomite application. Additionally, soil enzymes such as urease, catalase, invertase, phenol oxidase, and phosphatase also increased progressively, mirroring the rise in soil pH. This study identified increased soil pH as the critical factor influencing various soil parameters, especially the balance between AOA and AOB populations. Both AOB and AOA were sensitive to liming; AOA decreased while liming stimulated AOB abundance.

Calcium Losses from Reclaimed Sod-Podzolic Light Loamy Soil at Different Levels of Moisture Availability

In a 10-year laboratory experiment on columns, the migration mobility of calcium remaining in dolomite-reclaimed sod-podzolic soil after harvesting crops was studied. A “fund” of calcium compounds capable of migration in years with average long-term, excessive and insufficient levels of moisture has been identified. It was found that an increase in the volume of drained moisture contributed to an increase in unproductive calcium losses. The higher the dose of dolomite and the smaller the particle size, the greater the eluvial calcium loss. It is shown that the bulk of the calcium capable of migration was removed from the soil at the initial stage of washing. During the entire study period, migration calcium losses after pea harvesting exceeded losses after mustard cultivation. Empirical dependences describing the loss of calcium from the soil produced by dolomite in a wide range of doses have been developed. Various variants of the experiment were ranked according to the scale of calcium losses. It is shown that over 10 years of observations, the maximum calcium losses as a result of migration were characteristic of the variant of the experiment produced by dolomite flour calculated from the full dose of hydrolytic acidity. Calcium losses from soil reclaimed by dolomite particles of 5–7 and 7–10 mm in doses equal to 3 and 5 Hc were less.Key words: sod-podzolic light loamy soil, soil moisture availability, chemical reclamation, eluvial calcium losses, empirical models of migration process.

Growth response of Meranti Liberoid coffee seedling to liquid organic fertilizer and dolomite application

Liberica coffee is a type of coffee that can grow in soils with low pH and low nutrients. One of the efforts to increase the strength of the coffee seedling is by improving the planting media, through organic fertilizers and ameliorants application. This study aimed to analyze the effect of liquid organic fertilizer (LOF) and dolomite on the growth of Meranti Liberoid 2 (LIM 2) coffee seedlings. This research was conducted at the Pakuwon Experimental Station, Sukabumi, from April 2021 to January 2022. The research design used was a factorial 2 factor with 3 replications. The first factor was the LOF concentration (0, 5, and 10%), and the second was the dolomite dose (0; 2.5; 5.0; 7.5; and 10 g seedling−1). The results showed that the highest seedling height, leaf, and root dry weight of LIM 2 coffee seedlings was achieved by dolomite treatment of 7.5 g seedling−1 without LOF. The use of LOF can be an alternative to the need for dolomite to increase the growth of LIM 2 coffee seedlings.

Soil pH management for mitigating N2O emissions through nosZ (Clade I and II) gene abundance in rice paddy system

Soil nitrous oxide (N2O) is produced by abiotic and biotic processes, but it is solely consumed by denitrifying microbes-encoded by nosZ genes. The nosZ gene includes two groups i.e. Clade I and Clade II, which are highly sensitive to pH. Managing pH of acidic soils can substantially influence soil N2O production or consumption through nosZ gene abundance. Nevertheless, the response of nosZ (Clade I and Clade II) to pH management needs elucidation in acidic soils. To clarify this research question, a pot experiment growing rice crop was conducted with three treatments: control (only soil), low dose of dolomite (LDD), and high dose of dolomite (HDD). The soil pH increased from 5.41 to 6.23 in the control, 6.5 in LDD and 6.8 in HDD treatment under flooded condition. The NH4+ and NO3− contents increased and reached the maximum at 30.4 and 21.5 mg kg−1, respectively, in HDD treatment under flooding condition. The contents of dissolved organic carbon and microbial biomass carbon showed a swift rise at midseason aeration and reached maximum at 30.7 and 101 mg kg−1 in the HDD treatment. Clade I, Clade II and 16S rRNA genes abundance increased with the onset of flooding, and occurred maximum in the HDD treatment. A peak in N2O emissions (5.96 μg kg−1 h−1) occurred at midseason events in the control when no dolomite was added. Dolomite application significantly (p ≤ 0.001) suppressed N2O emissions, and HDD treatment was more effective in reducing emissions. Pearson correlation, linear regressions and principal component analysis displayed that increased soil pH and Clade I and Clade II were the main controlling factors for N2O emission mitigation in acidic soil. This research demonstrates that ameliorating soil acidity with dolomite application is a potential option for the mitigation of N2O emissions.

Growth and yield of soybeans at different dosages of NPK and dolomite fertilizer in ultisols of Bengkulu

Soybean cultivation in Ultisols is constrained by low soil pH and soil fertility levels. Dolomite and NPK fertilization are used to improve soil quality. The goal of this study was to find the best amounts of Dolomite and NPK fertilizer for black soybean growth and yield on Ultisols and how Dolomite and NPK fertilizers affect each other on Ultisols. This study used a completely random design (CRD) 2 factors and 3 replicates. The first factor was Dolomite with four levels: A1 = 0 ton/ha (control), A1 = 0.5 x Al-dd, A2 = 1 x Al-dd, and A3 = 1.5 x Al-dd. The second factor was NPK fertilizer with four levels: N0 = 0 kg/ha (Control), N1 = Urea 25 kg/ha, TSP 100 kg/ha, KCL 80 kg/ha, N2 = Urea 50 kg/ha, TSP 125 kg/ha, KCL 100 kg/ha, and N3 = Urea 75 kg/ha, TSP 150 kg/ha, KCL 120 kg/ha. The collected data were statistically analyzed using Analysis of Variance (ANOVA) at the 5% F level test. Research results show: 1) There is no interaction of single dose of dolomite and NPK on growth and yield of soybean Detam 4 2) Dolomite dose 1.5 times Al-dd gave the best effect on plant height and number of leaves 7 WAT and weight of 100 seeds, 3) There was no significant effect of giving NPK on soybean growth and yield except for the number of leaves 2 WAP.

PENINGKATAN PERTUMBUHAN DAN PRODUKTIVITAS KACANG TANAH DI LAHAN KERING MELALUI PEMBERIAN DOLOMIT DAN PUPUK NPK

[IMPROVEMENT OF PEANUT GROWTH AND PRODUCTIVITY IN DRY LAND THROUGH THE APPLICATION OF DOLOMITE AND NPK FERTILIZERS]. Dry land is commonly characterized by low pH and nutrient availability for peanut growth. Therefore, application of dolomite and NPK fertilizer might correct its characteristics. This study aimed to determine the appropriate dose of dolomite and NPK fertilizers to increase growth and productivity of peanut in dry land. This study was carried out from November 2019 to February 2020 at the Meteorological, Climatological, and Geophysical Agency, Indrapuri Experimental Garden, Aceh Besar, Aceh and used a randomized block design (RBD) with two factors and three replications. The first factor was three dosages of dolomite (i.e., 0, 250, and 500 kg/ha) and the second factor was three levels of NPK fertilizers (i.e., 0 kg/ha Urea+ 0 kg/ha SP36+ 0 kg/ha KCl), 25 kg/ha Urea + 50 kg/ha SP36 + 50 kg/ha KCl, and 50 kg/ha Urea + 100 kg/ha SP36 + 100 kg/ha KCl). The results showed that application of dolomite or NPK fertilizers had a significant effect on peanut yield components. Application of dolomite at 500 kg/ha or NPK fertilizers at 50 kg/ha Urea + 100 kg/ha SP36 + 100 kg/ha KCl increased peanut productivity by 10% and 9.23%, respectively compared to the control.

Buffer capacity as a method to estimate the dose of liming in acid soils

Objective: The study proposes using the dolomite buffer capacity (BCDolomite) as a method of estimating the lime requirement in soils that agronomically require a pH increase. Design/methodology/approach: In six soil samples with different levels of response to the application of dolomite, the organic matter (OM), the content of sand, silt and clay, pH, K, Ca, Mg and the potential acidity (Al+H) were determined. Assuming an apparent density of 1000 kg/m3 and a volume per hectare of 2000 m3, the soils were placed in polyethylene containers and treated with dolomite in doses equivalent to 0, 750, 1500, 2250 and 3000 kg/ha, establishing the BCDolomite as the inverse of the slope resulting from the relationship between the pH and the dose of dolomite. Results: In soils with low response to the dolomite, the content of clay and OM was 280 and 26 g/kg, respectively, and in high response soils, the content of clay and OM was 240 and 47 g/kg, respectively. In all cases, a simple and direct linear relationship was observed (R2 > 0.85; p < 0.05) in the relationship between pH and dose of dolomite. Limitations on study/implications: The results obtained under controlled conditions show that BCDolomite constitutes a viable method to estimate the lime requirement. Findings/conclusions: The BCDolomite showed sensitivity to the complexity of the clay fraction and to the organic matter in the soil, for which the dolomite requirement is equal to the product of the desired pH increase and the BCDolomite

Test Of Various Bulbil Sizes And Dolomite Dosages On Porang (Amorphophallus muelleri Blume.) Growth In Peat Media

Porang plant (Amorphophallus muelleri Blume.) is one of the plants that have the potential to be cultivated in peatlands needed to increase its production. This study aims to increase the growth of smallholder plants on peat media until six months after planting through bulbil size with dolomite treatment. The research type was a 4x3 factorial experiment arranged based on a Completely Randomized Design (CRD). The first factor is bulbil size which consists of four levels, e.g., B1 (5.0 g-7.5 g), B2 (>7.5 g-10 g), B3 (>10 g-12.5 g), B4 (> 12.5 g-15.0 g) and the second factor dose of dolomite consists of three levels, e.g., D1 (2.5 ton.ha-1) D2 (5.0 ton.ha-1) D3 (7.5 ton.ha-1) -1). These two factors resulted in 12 treatment combinations, with three repetitions. Each experimental unit consisted of three plants. Parameters observed were growth power, plant height, stem diameter, crown width, rachis length, number of leaves, number of tillers, and number of tubers formed. The results showed that the application of dolomite could improve some of the chemical properties of peat soil. The bigger the bulbil size, the better the growth of people and the administration of 7.5 tons of dolomite.ha-1 increased several plant growth parameters such as growth power and plant height.

Challenges in Reducing Phytotoxicity of Metals in Soils Affected by Non-Ferrous Smelter Operations

Lime is one of the effective agents for reducing the phytoavailability of metals in contaminated acidic soils. However, previous studies have shown that lime alone cannot reduce metal phytotoxicity to the desired extent in such soils. The goal of this study was to evaluate the effect of different amendment combinations (lime with and without Feand/or Mn-based amendments) on plant growth. A sample of Histosol (0-5 cm) was collected around a Cu/Ni smelter near Monchegorsk, Murmansk region, exhibiting total Cu and Ni concentrations in the soil of 6418 and 2293 mg kg-1, respectively. Likewise, a sample of forest litter (0-15 cm) was collected around a Cu smelter near Revda, Sverdlovsk region, exhibiting total Cu concentration in the soil of 5704 mg kg-1. Fe-Mn oxides were sourced from ferromanganese nodules in the Gulf of Finland, and iron powder was used as a precursor for iron oxides. Perennial ryegrass was grown in pots for 21 days under controlled laboratory conditions. Two dolomite doses were tested: 5% w/w (giving a soil pH of 6.5) and 20% w/w (giving a soil pH of 7.4). Over-liming stunted plant growth; therefore, the dolomite dose was set at 5% in the further experiments of the study. Importantly, the addition of 0.5% and 1% of Fe-Mn-oxides or iron powder did not improve the efficacy of the lime amendment in promoting plant growth in the soils. Therefore, the issue of reducing plant exposure to metals remained unresolved in the soils under study.

Liming of acid soil and the interaction with soil pH and corn productivity

Liming is the dominant technology to treat acidic soils, which is indicated by low soil pH. Improvement of soil pH can be made using dolomite application to overcome aluminum (Al) toxicity and release phosphate and potassium nutrients to become available for plants. This study aims to test the effectiveness of dolomite in improving soil pH, corn productivity, and dolomite dose. Field testing was done in Pasar VI Kwala Mencirim Village, Sei Bingai District, Langkat Regency, North Sumatra from April to August 2020 using a non-factorial randomized block design with seven treatments and four replications: Dolomite 0 X (D0) 0 ton ha−1, Dolomite 0.5 X (D1) 1 ton ha−1, Dolomite 1.0 X (D2) 2 ton ha−1, Dolomite 1.5 X (D3) 3 ton ha−1, Dolomite 2.0 X (D4) 4 ton ha−1, Dolomite 2.5 X (D5) 5 ton ha−1, and Standard Dolomite (DS) 2 ton ha−1. Dolomite treatment was given one week before planting by sowing evenly on the experimental plot. They showed that dolomite application to D1, D2, D3, and D4 could increase soil pH, resulting in higher plant height and corn production than D0 and DS. The optimum dose of dolomite is 2 ton ha−1 on acid soils. Liming acid soil can increase soil pH from acid to neutral and increase corn production by 1.91 times compared to without dolomite application.

PENGARUH PEMBERIAN DOLOMIT DAN PEMUPUKAN NPK TERHADAP PERTUMBUHAN DAN HASIL OKRA (Abelmoschus esculentus L.) PADA TANAH HISTOSOL

Abstract Histosol is an organic soil with a high acidity value (pH 4.5) and low levels of nutrients N, P, and K that is effects to plant growth and yield. This study aims to examine the effect of dolomite and NPK fertilization on the growth and yield of Okra (Abelmoschus esculentus L.) on Histosol soil. This research was conducted in the Experimental Garden of the Faculty of Agriculture, Teuku Umar University, West Aceh. This study used a factorial 4 x 4 randomized block design (RBD) with 3 replications. The factors studied include: 1) Dolomite factor (D) consists of 4 levels, namely: D0= without liming, D1= 22.5 grams/polybag, D2= 45 grams/polybag, D3= 67.5 grams / polybag; 2) NPK fertilizer factor (N) consists of 4 levels, namely: N0= zero NPK fertilizer application, N1= 11.25 gram/polybag, N2 = 18.75 grams/polybag, N3= 26.25 grams/polybag. The results showed that dolomite dose had a very significant effect on plant height, stem diameter and number of leaves of okra plants aged 15, 30, 45 and 60 HST. Very significant effect on the length of the okra fruit aged 73 HST and significant effect on the weight of the fruit age 73 HST, but no significant effect on fruit diameter, number of fruit age and production per hectare (tons) 73 HST. NPK fertilizer has a very significant effect on plant height and stem diameter aged 15, 30, 45 and 60 HST. Very significant effect on fruit length and diameter okra fruit aged 73 HST. Not significant effect on the number of fruits, fruit weight and per hectare production (tons) of okra aged 73 HST. There was no interaction between dolomite and NPK fertilizer from all treatments.Keywords : Histosol, acidity, liming and fertilizing, growth and yield of okra plants

Influence of Liming on Soil Chemical Properties and Plant Growth of Pineapple (Ananas Comusus L.Merr.) On Red Acid Soil, Lampung, Indonesia

ABSTRACTRed acid soil is generally distributed in humid tropical areas under high rainfall. The main constraint is usually the extremely low pH of the soil due to the very intensive leaching of the bases from the soil. At the same time, however, the soluble micro elements, such as iron, are high. This can cause plant toxicity. The liming of acidic soils is normally performed to reduce the iron toxicity as the first step toward providing a balanced nutrition for cultivated plants. The objective of this study is to determine the effects of liming on the soil pH, on the decrease of iron in the soil and on the growth of the pineapple. The research was done in the Greenhouse of the Research and Development Department, PT Great Giant Pineapple, Lampung, Indonesia, from November 2015 to April 2016. The design of the experiment was arranged as a completely randomized design with seven treatments and three replications, consisting of: No dolomite (D0), dolomite 1 t ha−1 (D1), dolomite 2 t ha−1 (D2), dolomite 3 t ha−1 (D3), dolomite 4 t ha−1 (D4), dolomite 5 t ha−1 (D5) with added Fe-EDTA and for the control treatment, no dolomite and no Fe-EDTA (C0). The results showed that an increase in the dolomite dose can increase the pH, potassium (K), calcium (Ca) and magnesium (Mg) in the soil and can decrease the iron (Fe) in the soil significantly. Increasing the pH, K, Ca and Mg and decreasing the Fe in the soil were seen to influence the growth of the pineapple. In particular, the leaf area of the pineapple plant increased considerably. The other parameters also increased, but not significantly.

PENGARUH DOLOMIT DAN PUPUK P TERHADAP PERTUMBUHAN DAN PRODUKSI KACANG TANAH (Arachis hypogaea L.) SEBAGAI TANAMAN SELA DIANTARA KELAPA SAWIT DI LAHAN GAMBUT

The research aims to study the interaction of dolomite dose and P fertilizer application on growth and yield of peanut plants as intercropped between palm oil on peatland. The study was conducted in the agriculture experimental station Faculty of Agriculture, University of Riau, Rimbo Panjang village, Kampar District, from December 2015 to April 2016. The research utilizes a Randomized Complete Block Design (RCBD), which consists of two factors. The first factor is dolomite consists of 3 levels (0, 500 and 1000 kg/ha) and second factor P fertilizer consists of 4 levels (0, 23, 46 and 69 kg P2O5/ha), each combination has 4 replication. The parameters observed were plant height, number of primary branches, flowering age, harvesting age, number of pods, number of seeds per pods, the weight of dry seeds and filled seeds/m2, percentage of filled seeds, the weight of 100 seeds. The data of each parameter were analyzed with analysis of variance (ANOVA) followed by Duncan's New Multiple Range Test (DNMRT) at 5% level. The results showed that the increase of weight of dry seeds and filled seeds /m2were significant at the application of 69 kg P2O5/hafollowed by 500 kg dolomite/ha and percentage of filled seeds at the application of 69 kg P2O5/hafollowed by 1000 kg dolomite/ha compared to without P fertilizer and dolomite, whereas in plant height, number of primary branches, flowering age, harvesting age, number of pods, number of seeds per pods and weight 100 seeds were not significant each combination of treatments.

Effect of Amelioran Material on Soil Chemical Properties of Incubated Peat Planting Media in Polybag

The aim of this study was to obtain the best combination of types and doses of ameliorant materials: dolomite, rock phosphate, and mineral soil to improve the chemical properties of soil which was incubated for one year in peat media in polybag. The research was conducted in May 2015 - April 2016 in the experimental garden in the village of Sijambi, Tanjungbalai, North Sumatra. Elevation 3 m above sea level, with the C2 (Oldeman) climate type. The experiment was compiled using a Randomized Block Design, with 3 treatments of ameliorant material. The three ameliorant materials were tested for 3 doses. The addition of dolomite treatment: A1=0.45 kg polybag-1; A2=0.90 kg polybag-1; A3=1.35 kg polybag-1. The addition of rock phosphate treatment: A4=0.45 kg polybag-1; A5=0.90 kg polybag-1; A6=1.35 kg of polybag-1. The addition of mineral soil treatment: A7=0.45 kg polybag-1; A8=0.90 kg polybag-1; and A9=1.35 kg polybag-1.The results shown that the highest dose of dolomite (1.35 kg polybag-1) improved soil chemical properties, including soil pH and alkali cations (K, Ca and Mg) on incubated peat soil. Addition of rock phosphate with the highest dose of 1.35 kg polybag-1 (A6) increases available phosphorus and soil CEC. Addition of mineral soil dose of 0.90 kg polybag-1 (A8) increases soil CEC. In the analysis of total soil nitrogen, the highest increase was obtained by adding dolomite dose of 0.45 kg.polibag-1 (A1).

Effect of dolomite amendment of acid Andosols on the performance of two green beans varieties in the Cameroon Western Highlands

Soil acidity is a major factor limiting green beans (Phaseolus vulgaris L.) production in the Cameroon western Highland. A field experiment (split-plot layout) was conducted with seven dolomite treatments (tons ha-1): control or T0 (0), T1 (0.5), T2 (1), T3 (1.5), T4 (2), T5 (2.5) and T6 (3). Soil physico-chemical properties were determined meanwhile growth and yield parameters were collected weekly for a month and analyzed statistically. Results revealed that control soils were texturally silty sandy. The exchangeable bases (except Na), cation exchange capacity (CEC), base saturation and available phosphorus were very high. They acidity was moderate to high (5.2 to 5.6) while organic matter was very high (% dry mass) and of moderate to good quality (11<C/N ratio<13). Crop variety showed a highly significant difference (P<0.001) for all growth and yield parameters, with Cogito producing the longest (13.88 cm), most numerous (40.94 pods per plant) and highest (16.96 tons ha-1) extrafine pods. Dolomite doses revealed no significant effects (P>0.05) on crop parameters, although highest yield (13.61 tons ha-1) of extrafine pods came from 2 tons ha-1. The dolomite dose versus variety interaction showed no significant difference (P>0.05). Farmers ought to improve soils with compost and cover crops to check nutrient leaching and erosion.

Modification of Growing Medium for Container Melon (Cucumismelo L.) Production Using Goat Manure and Dolomite

The growth of melon plant requires soil rich in organic matter, well drainage, and soil pH 6.0 - 7.0. The adverse conditions are found on mostly red-yellow podsolic of Ultisol. The objective of this research was to evaluate the application of goat manure and dolomite on growth and yield of melon. The research was held from June until September 2015 in Kandang Limun, Bengkulu City. Completely Randomized Design was arranged involving goat manure doses consisted of 0 kg polybag-1, 3 kg polybag-1, and 6 kg polybag-1. Another factor was that the dose of dolomite consisted of 0 g polybag-1 (0 tons ha-1), 100 g polybag-1 (2 tons ha-1) and 200 g polybag-1 (4 tons ha-1). Treatments were replicated three times; each experimental unit consisted of 4 polybags of plants. The result of this research revealed no interaction between goat manure and dolomite in affecting the vegetative growth of plants. The interaction between goat manure and dolomite was found affecting fruit weight, fruit diameter and the thickness of the edible fruit part. The highest values for fruit weight, fruit diameter, and edible fruit thickness were achieved on 3 kg polybag-1 goat manure and 200 g polybag-1 dolomite treatment, which were 725.25 g, 17.14 cm, and 2.99 cm respectively. Goat manure dose of 6 kg polybag-1 increased stem diameter (5.5 mm) and fruit sweetness (8.09 0Brix) compared to treatment without manure which was 5.43 mm and 7.31 0Brix.

Pemupukan N, P, K, Dolomit, dan Pupuk Kandang pada Budidaya Kedelai di Lahan Kering Masam

ABSTRACT<br /><br />The imbalanced supply-demand of soybean is the main reason of soybean import in Indonesia. One of the efforts to increase of soybean production was expanding the planting area to acid soil with a low pH, high content of Aluminum, and low nutrient availability, through giving ameliorant, such as liming organic materials, and mineral fertilization.This study was aimed to obtain the best combination of fertilizer and amelioran for soybean production in acid soil. The study was conducted in experimental station of Tenjo, Bogor from November 2015 to March 2016. The experiment used a randomized complete block design with two factors. The first factor was combinations of fertilizer and amelioran, i.e., P0 (without fertilization); P1 {25 kg urea + 75 kg SP-36 + 50 kg KCl + dolomite ¼ x Aldd (805 kg) ha-1}; P2 {25 kg urea + 75 kg SP-36 + 50 kg KCl + dolomite ¼ x Aldd (805 kg) + 1,250 kg of manure ha-1}; P3 {50 kg urea + 75 kg SP-36 + 50 kg KCl + dolomite ¼ x Aldd (805 kg) + 2,500 kg of manure ha-1}; P4 {75 kg urea + 150 kg SP-36 + 100 kg KCl + dolomite ¼ x Aldd (805 kg) + 2,500 kg of manure ha-1}; P5 {75 kg urea + 150 kg SP-36 + 100 kg KCl + dolomite ½ x Aldd (1,610 kg) ha-1}; P6 {75 kg urea + 150 kg SP-36 + 100 kg KCl + dolomites 1 x Aldd (3,220 kg) ha-1}. The second factor was soybean varieties of Tanggamus and Anjasmoro. The results showed that application of 75 kg urea + 150 kg SP-36 + 100 kg KCl + dolomite ½ x Aldd (1,610 kg) produced the highest productivity (2.91 ton ha-1), but it was not different from reducing the dose of dolomite into ¼ x Aldd (805 kg) with the addition of 2,500 kg of manure.<br /><br />Keywords: Al saturation, chemical properties of soil, nutrient uptake, produktivity, soil amelioran

Optimasi Pemberian Lumpur Aktif dan Dolomit dalam Pengolahan Limbah Cair Pabrik Kelapa Sawit

The palm oil mill effluent (POME) generally has very high of BOD and COD contents, so it must be processed before it is drained to the body water. The purpose of this research was to determine the capability of active sludge and dolomite rate and the combination both of them in reducing the palm oil industry liquid waste. This research was conducted in December 2016 until January 2017 at Chemical Analysis Laboratory, State Polytechnic of Lampung. This research consists of two factors. First factor was the use of active sludge (without active sludge and 1 kg of active sludge), and the second factor was dolomite rate (0,3%, 0,6%, and 0,9% dolomite).The results obtained were calculated bassed on average repetitions then at compared with the value of initial analysis and quality standard, but the COD value is calculated based on the percentage of the reduction value, and all the observed values are presented in the graph. The results showed that the 1 kg active sludge treatment was more effective in degrading the wastewater than with no active sludge. The increased dose of dolomite to 0.9% combined with 1 kg of active sludge will be followed by an increase in pH (6,23) and DO (0,26 mg.l -1 ), but decrease COD to 53,7%, TSS to 810 mg.l -1 , turbidity value to 700 NTU, and potassium content to 4865 mg.l -1 . Keywords: chemical oxygen demand, dissolved oxygen, palm oil mill effluent, total suspended solid, turbidity

Pertumbuhan Vegetatif, Akar, dan Nodula Tanaman Kacang Hijau (Vigna radiata L.) Akibat Pemberian Kompos Azolla (Azolla pinnata) Bentuk Pellet dan Calsium Carbonate (CaCO3) Tanah Ultisols Masam

Ultisols are the most extensive land order, reaching 48.3 million hectares or 29.7% of the land area of Indonesia. Development of food crops and horticulture farming on this land will face many obstacles related to the nature of this land. Ultisols are soil that is sensitive to erosion, low fertility and reacts sourly to very acidic.Ultisols are generally low in soil fertility caused by high levels of acidity, low nutrient content of N, P, K, Ca, Mg, S and Mo and high levels of Al, Fe and Mn elements which often reach levels that are harmful to growth. . In addition, the high element Al, Fe da Mn in Ultisols can also bind P nutrients into insoluble and not available to plants. This study aims to obtain the composition of azolla (Azolla pinnata) form of pellets and calcium carbonate (CaCO3) which can provide the highest growth and yield of mungbean (Vigna radiata) plants in acidic Ultisols. The study was carried out in the Lampung State Polytechnic practice garden, from July 2018 to October 2018. The study was arranged in factorial in a randomized block design (RBD) with 16 treatment combinations and 3 replications, so that there were 48 experimental units. The treatment combination is as follows: The first factor is the dose of pelleted azolla compost (A) which consists of 4 levels, namely: a0 = without azolla compost, a1 = 10 tons ha-1, a2 = 20 tons ha-1, and a3 = 30 tons ha- 1. The second factor is the Dolomite dose (D) which consists of 4 levels, namely: c0 = without dolomite c1 = 1.5 tons Ha-1Dolomite, c2 = 3 tons Ha- 1Dolomite, and c3 = 4 tons Ha-1 Dolomite. The target to be achieved in this study is to find out the response of the variables observed, namely: (1) plant dry weight (g), (2) root dry weight and (3) number of root nodules (grains). Pelleted azolla compost increase the growth of root nodules, root dry weight and shoot dry weight of mung bean on the Taman Bogo Lampung Ultisols soil. Dolomite increases the number of root nodules but has no significant effect on the root dry weight and shoot dry weight of mungbean on the soil of Taman Bogo Lampung Ultisols. Compost azolla and dolomite lime work independently on the lands of the Bogo Lampung Taman Ultisols. Keywords: Ultisol, Pelleted Azolla Compost, Dolomite, Mung Bean (Vigna radiata L)

Growth and Yield Response of Bambara Groundnuts (Vigna subterranea L ) to the Mixed of Peat and Mineral Soil with Several Dosage of Dolomite

Bambara groundnut (Bogor groundnut) was an alternative food crops having high nourishing, better taste and bigger size nut than the soy beans and peanuts. To meet the need for food and industrial needs, the program to increase production of Bogor groundnut was required, one of which is the use of peat as a growing medium using the technology of mixing peat and mineral soil. The research objective was to obtain a mixture of peat with mineral soil and dolomite lime dose suitable for the highest growth and yield of Bogor groundnut. This study was conducted in May 2015-September 2015 in the Greenhouses of Faculty of Agriculture, University of Bengkulu. The experiment was arranged in a completely randomized design (CRD) with two treatment factors and three replications. The first factor was soil mix of peat and mineral soil (G0: 100% peat + 0% mineral soil; G1: 75% peat + 25% mineral soil; G2: 50% peat + 50% mineral soil; G3: 25% peat + 75% mineral soil) and the second factor was the dose of dolomite (D0: without lime dolomite; D1: 3 ton ha-1 and D2: 4 ton ha-1). The results showed that the response of biomass dry-weight to a mixture of peat with mineral soil was influenced by the dose of dolomite, but there was no interaction on other variables. Treatment of a mixture of peat 100% alone was capable of generating the highest number of leaf, biomass fresh- and dry-weight. Bogor groundnut plants showed the same response to the dose variation of dolomite lime.Keywords: Bogor groundnut, peat, mineral, dolomite