Effect of humic acid on the growth and yield of two maize (Zea mays L.) cultivars on andisol

One way to improve maize (Zea mays L.) production is through land extension using Andisol land. However, Andisol soil has phosphate (P) fixation problem due to the high amorphous material. Hence, the use of organic material in the form of humic acid that has greater affinity to amorphous minerals is recommended to solve the problem. This research was conducted in February-May 2017 at Tri Dharma field of Faculty of Agriculture, Universitas Gadjah Mada. The Andisol land used has a low available P category from Datar, West Java and Wonosobo, Central Java. This research was arranged in a Randomized Complete Block Design (RCBD), consisting of two factors. The first factor was maize cultivar (Bisi-2 and Pioneer-35). The second factor was the doses of humic acid, consisting of control treatment (without fertilizer and humic acid), NPK without humic acid, and NPK + humic acid at 5%, 10%, and 15%. The percentage of humic acid given, based on the amount of NPK 16:16:16 fertilizer, was 350 kg.ha-1. Fertilization was applied three times 100 kg.ha-1 on 1 WAP, 150 kg.ha-1 at 3 WAP and 100 kg ha-1 at 7 WAP. The results is, humic acid treatment had the same effect with NPK fertilization treatment only and control on P available Andisol soil. Humic acid, also has the same effect with NPK fertilizer treatment in increasing the yield component of 100 seeds weight, dry weight of seeds, harvest index, length of cobs and productivity

Accumulation Levels of Available Cu and Cu Absorption in Corn in Ultisolss and Alfisolss After the Addition of Fly Ash and Organic Materials

Fly ash was a byproduct of burning coal in thermal power plants that can be used in agriculture as a source of micronutrients. This study aimed to determine the effect of fly ash combined with Biochar and Manure on the chemical properties of the soil, plant growth, and the absorption of Cu corn plants. The study design used a randomized design of factorial groups, with soil type factors namely Alfisols and Ultisols with three repeats. Agronomic observations include plant height, dry weight of roots and headers. Laboratory analysis includes preliminary soil, Fly Ash, Manure, Biochar, soil analysis after harvest, and Cu in leaf. The results showed that the availability of Cu elements in Ultisols was higher by 5.37 mg/kg than Alfisols with an average of 3.90 mg/kg.  Cu absorption in maize crops grown in Alfisols soil was greater with an average of 54.7 mg/g when compared to those planted in Ultisols soil by an average of 50.3 mg/g. The treatment between Fly Ash and Manure in a ratio of 1:1 has a tendency to increase Cu absorption with a value of 68 mg/g. Alfisols soil was significantly correlated with organic matter to Cu absorption in Corn plants with a value of R= 0.827. The conclusion of this study was that the availability of Cu elements in Ultisols soil was higher than in Alfisols soil and Cu uptake in corn plants was lower after being treated with the addition of manure and Biochar and corn plant growth was better

Interaction of Peat Soil and Sulphidic Material Substratum: Role of Peat Layer and Groundwater Level Fluctuations on Phosphorus Concentration

Phosphorus (P) often becomes limiting factor for plants growth. Phosphorus geochemistry in peatland soil is associated with the presence of peat layer and groundwater level fluctuations. The research was conducted to study the role of peat layer and groundwater level fluctuations on P concentration in peatland. The research was conducted on deep, moderate and shallow peat with sulphidic material as substratum, peaty acid sulphate soil, and potential acid sulphate soil. While P concentration was observed in wet season, in transition from wet to dry season, and in dry season. Soil samples were collected by using peat borer according to interlayer and soil horizon. The results showed that peat layer might act as the main source of P in peatland with sulphidic material substratum. The upper peat layer on sulphidic material caused by groundwater level fluctuations had no directly effect on P concentration in the peat layers. Increased of P concentration in the lowest sulphidic layer might relate to redox reaction of iron in the sulphidic layer and precipitation process. Phosphorus concentration in peatland with sulphidic material as substratum was not influenced by peat thickness. However, depletion or disappearance of peat layer decreased P concentration in soil solution. Disappearance of peat layer means loss of a natural source of P for peatland with sulphidic material as substratum, therefore peat layer must be kept in order to maintain of peatlands. [How to Cite: Arifin F, B Radjagukguk and BH Purwanto. 2014. Interaction of Peat Soil and Sulphidic Material Substratum: Role of Peat Layer and Groundwater Level Fluctuations on Phosphorus Concentration. J Trop Soils 19: 171-179. Doi: 10.5400/jts.2014.19.3.171

Kelarutan Fosfat dan Ferro pada Tanah Sulfat Masam yang Diberi Bahan Organik Jerami Padi

Phosphate and Ferrous Solubilty on Acid Sulphate Soils Treated with Rice Straw (A. Fahmi, B. Radjagukguk, and B. H. Purwanto): The objective of this research was to investigate the effect of application of organic matter from rice straw (RS) on phosphate and Fe2+  solubility in the acid sulphate soils.  The research was conducted in the glass house consisting of the three treatment factors using the completely randomized design with three replication.  The first factor was soil condition : continuous application of  RS and without application of RS during the last 5 years.  The second factor was fresh application of RS ; with application and without application, whereas the third factor was phosphate application consisting 3 rates of SP – 36 fertilizers (0.5; 1,0 and 1.5 of application dossage). The result showed the three factors interaction had a significant influence on soil pH at 2 weeks after planting, whilst   interaction between RS application and soil condition had a significant influence on soil pH, available phosphate at 4, 6 and 8 weeks after planting.  The interaction between RS application and phosphate fertilizers rate had a significant influence on soil pH 4 weeks after planting, and on available phosphate at 8 weeks after planting.  The main effect of RS application was significant on exchangeable Fe and soil pH at all observations periods

The Leaching of Iron and Loss of Phosphate in Acid Sulphate Soil Due to Rice Straw and Phosphate Fertilizer Application

Low phosphorus (P) availability and high iron (Fe) concentration are the dominant characteristics of acid sulphate soils (ASS).  Optimum agricultural management practices are required to leach the excess Fe2+  and to prevent or minimize loss of P from the soil in order to obtain conditions favorable for rice growth. The aim of this experiment was to study the effect of organic matter (OM) application in the form of rice straw (RS) on leaching of Fe and loss of P in an acid sulphate soil. The experiment was conducted in the glasshouse consisting of three treatment factors utilizing the completely randomized design with three replications. The first factor was soil condition consisting of continuous application of RS and without RS during the past five years. The second factor was application of fresh RS consisting of fresh RS application and without fresh RS application, whereas the third factor was P application consisting of three rates of SP-36 fertilizer (0.5, 1.0 and 1.5 times of the recommended rate). The results showed that RS application was effective in preventing P loss from the soil at 6 weeks after planting (WAP) and decreased the pH of leachate at all observations time but it increased Fe2+ concentration in leachate (0.07-0.42% Fe2+ in the soil were leached or 2-5 folds higher than without RS application)

N2O-N emissions from organic and conventional paddy fields from Central Java, Indonesia

To evaluate the effect of farming system on gaseous emission of N from soil, the measurements of nitrous oxide (N2O) were taken in organic and conventional paddy fields in tropics. Eleven soil samples from organic and neighboring conventional sites in Central Java, Indonesia were incubated at two different moisture contents expressed as water filled pores (WFPS), namely 75% WFPS and 100% WFPS. Emission of N2O-N at 75% WFPS was significantly higher in conventional management than in organic management. At 100% WFPS, the N2O-N emission was also higher in conventional than in organic farming system. Although it was not significantly different, it has significantly and positively correlations with SOC, total N and initial mineral N content. Due to the swelling ability of the high clay which is contained in soil samples, less N2O-N emission in 75% WFPS than in 100% WFPS was observed in the present study. The range of N2O-N emission at 75% WFPS was 0.01 - 0.03 kg N2O-N/ha in organic farming and 0.005 - 0.16 kg N2O-N/ha in conventional farming; for organic farming at 100% WFPS, the N2O-N emission was 0.04 - 61 kg N2O-N/ha and in conventional farming was 0.08 - 74 kg N2O-N/ha. This study concludes that organic farming in paddy fields might have more promising potential to mitigate N2O-N emission than conventional farming in paddy fields

Effect of long of landuse and cropping system on soil fertility and cassava yield

A study that was aimed to determine the influence of long of land use and cropping systems on soil fertility and yield of cassava conducted at centre of cassava in Sukadana Subdistrict, East Lampung. Survey was conducted to characterize soil fertility due to the long of landuse and cassava cropping system from February to September 2014. Treatments of cropping system and long of land use observed involving: (1) Cassava monoculture for more than 30 years, (2) Cassava monoculture for 10- 30 years, (3) Cassava monoculture for less than 10 years, (4) Intercropping cassava and maize, (5) Intercropping cassava and groundnut, (6) Crop rotation of cassava and maize, and (7) Crop rotation of cassava and groundnut. The results showed that concentration of all macro nutrients of cassava monoculture for more than 30 years was lower than cassava monoculture for less than 10 years including the decrease of 11% of soil pH, 49% of total N , 66% of organic C, 57% of available P, 64% of K, 70% of Ca, 55% of Mg and 37% of CEC. Intercropping or crop rotation of cassava with legume or non-legume increased the soil pH, organic C, total N, K, Ca and Mg and decreased exchangeable Al. The changes in soil chemical and physical properties due to different cropping system affected the yield of cassava. The highest yield of cassava was obtained by crop rotation of cassava and maize, while the lowest was monoculture for more than 30 years. Cassava monoculture grown for 10-30 years or more than 30 years had low soil fertility so that the yield of cassava was also low. The yield of cassava in the rotation system was higher than the intercroppin

The Role of Peat Layers on Iron Dynamics in Peatlands

The Role of Peat Layers on Iron Dynamics in Peatlands (A Fahmi, B Radjagukguk, BH Purwanto and E Hanudin): The research aimed to study the effect of peat thickness and humification stage of the peat material on Fe solubility at the peatlands with sulfidic material as substratum.  The research was conducted at three conditionals of ombrogen peatlands ie ; deep, moderate and shallow peat. Soil samples were collected by using peat borer according to interlayer (the border layer of peat and mineral layer) and conditional of soil horizons.  The sample point depth were (cm) G.s2 : 25, G.s1 : 50, Int.s : 70,  M.s1 : 90 and M.s2 : 100 for shallow peat, G.m2 : 47, G.m1 : 100, Int.m : 120 and M.m1 : 135 for moderate peat and G.d3 : 50, G.d2 : 150, G.d1 : 200, Int.d : 220  and M.d1 : 235 for deep peat respectively.  The results showed that most of Fe on the tested soils was found in organic forms. The peat layers above the sulfidic material decreased the Fe2+ solubility at peatlands. Fe2+ concentration in peat layer decreased with its increasing distance from sulfidic material. There was any other processes beside complexation and chelation of  Fe2+  by humic material and its processes was reduction of Fe3+ and this conditions was reflected in redox potential values (Eh)

Adsorption and release of soil P in andisols under organic and conventional vegetable farming system

Phosphorous (P) is strongly adsorbed by soil components, such as soil organic matter and soil amorphous minerals in Andisols, which have been identified as an influential factor in adsorption and release of soil P. The aim of this study was to characterize the pattern of soil P adsorption and release in both organic and conventional vegetable farming systems in Merbabu Mountain area, Indonesia. Soil samples were collected from soil layers (0 cm to 20 cm and 20 cm to 40 cm) in organic and conventional farming systems. The result showed that the highest adsorption rate was found in organic farming systems at a depth of 20 cm to 40 cm. The lowest adsorption rate was found in conventional farming systems with low input of organic matter at a depth of 20 cm to 40 cm. A higher rate of P release was also found in organic farming systems with a low input of organic matter. It can be concluded that vegetable soils in organic farming systems are not only highly capable of adsorbing P but also capable of releasing P rapidly