Water Retention and Saturation Degree of Peat Soil in Sebangau Catchment Area, Central Kalimantan

Water is an essential factor in forming, utilization, management, and sustainability of peat soil. This study was to obtain characteristics of water retention and porosity of peat soil. Peat samples were taken from the Natural Laboratory of Peat Forest, Central Kalimantan at shallow, medium, and deep peat at 0-50cm (surface) and 50-100 cm (subsurface), while laboratory analyses carried out at Soil Laboratory, Universitas Gajahmada. The result shows that volumetric moisture content at the surface lower than subsurface, except for deep peat. The total pore for the surface was 84.67-86.98%, while subsurface layers were 83.53-86.93%. For surface layer, saturated degree (S) medium peat higher than shallow and deep peat, while for shallow subsurface peat higher than medium and deep peat. S value all pF levels of surface for medium and deep peat higher than the subsurface. Bulk density for surface was 0.094g.cm-3 (rb(wet)) and 0.22g.cm-3(rb (dry)) for shallow peat while medium peat are 0.084–0.087g.cm-3(rb(wet)) and 0.18–0.20g.cm-3(rb(dry)), deep peat 0.064–0.090g.cm-3(rb(wet)) and 0.11–0.16g.cm-3(rb(dry)). For subsurface, bulk density of medium peat are 0.094–0.107g.cm-3 (rb(wet)) and 0.16–0.20g.cm-3 (rb(dry)), deep peat are 0.067–0.090g.cm-3 (rb(wet)) and 0.10–0.17g.cm-3 (rb(wet)). The particle density of surface and subsurface for shallow peat higher than medium and deep peat, with values 0.67-0.77g.cm3, 0.61-0.66g.cm3, and 0.53-0.63g.cm3 for shallow, medium, and deep peat, respectively. Total pores for the surface layer decrease with increasing dry bulk density (R = 0.624) and particle density (R = 0.375). This fact seems to confirm a directly proportional relationship between parameters bulk and particle density with total pores.

Vermicompost Buffering Capacity to Reduce Acidification of Pb and Cd Contaminated Inceptisols and Entisols

Contamination of heavy metals on the soil leads to an increase in its acidity. Vermicompost application is commonly used to improve the properties of soil. The study was carried out to determine the reduction of the acidity in Pb and Cd contaminated soils under the application of vermicompost. Two laboratory experiments were set using Completely Randomized Design (CRD) with two factors. The first factor was soil samples, vis Inceptisols, and Entisols, and the second factor was the rates of vermicompost, consisted of 0, 5, 10, 15 g kg-1. The treatment combination was repeated three times. The soils were pretreated with 10 mg kg-1 Pb or Cd using Pb(NO3)2 and Cd(NO3)2. Three hundred kg soil sample was incorporated with vermicompost and placed in a 500 ml plastic bottle. The mixtures were incubated for eight weeks, and the moisture of the soil was maintained at field capacity. The acidity and soil temperature were monitored every week. The study indicated that Pb contaminated soil acidity increased to the sixth week of the incubation and decreased afterward. However, the acidity of Cd contaminated soil was consistently increased during the incubation. Treatment of vermicompost significantly lowered the acidity of both Pb and Cd contaminated soils. Contaminated Entisols had a higher response to the application of vermicompost than that of Inceptisols. This finding is significant in assessing acidity risk and possible management intervention for Pb and Cd contaminated soils.

The Phytoextraction of Copper from Tropical Soil 21 Years after Amendment with Heavy-Metal Containing Waste

Several particular plants are suggested to extract significant parts of heavy metals from soils and accumulate them in their roots and shoots. This research aimed to study the phytoextraction of Cu by several plants from heavy-metal contaminated tropical soils. Soil samples collected from plots treated in 1998 with 0, 15 and 60 Mg industrial waste ha-1 were planted with three different plants, i.e., caisim, water spinach, and lettuce. Plant parts (roots and shoots) and soil samples were harvested after a four-week growth period and analyzed for plant and soil Cu. The results show that the growth of plants was depressed by the increase in the soil Cu (extracted by 1 N HNO3) as affected by waste levels, with water spinach being the most progressive and produced the most significant biomass. The absorption of Cu by caisim and water spinach increased with the soil extracted Cu (linear R2 = 0.71* for caisim and 0.32* for water spinach) and accumulated greater in plant roots than that in shoots. The translocation factor (TF << 1.00) indicates that all plants were good Cu phytostabilizators rather than phytoextractors, with water spinach being the best Cu extractor.

An Evaluation of MODIS Global Evapotranspiration Product as Satellite-Based Evapotranspiration Data for Supporting Precision Agriculture in West Papua - Indonesia

Precision Agriculture has been a significant issue since the middle of the 1980s. Evapotranspiration is one of the main parameters in precision agriculture to analyze real water needs in the agriculture area and managing water resources. Traditionally evapotranspiration estimates by directly measured methods, i.e., lysimeter, pan-evaporation, eddy covariance, Bowen ratio, soil water, and climate data analysis. These methods are expensive techniques with low spatial representativeness. The utilization of remote sensing technology is expected to be an alternative solution for providing evapotranspiration data with a cost-effective and high spatial representative. This research aims to evaluate the MODIS global evapotranspiration as satellite-based evapotranspiration in estimating evapotranspiration in West Papua. Four (4) statistical parameters, i.e., mean error (ME), root means square error (RMSE), relative bias (RB), and mean bias factor (MBF), are using for evaluation. The research showed that MODIS global evapotranspiration was overestimated in estimating evapotranspiration in West Papua. However, MODIS global evapotranspiration has an acceptable accuracy in estimating evapotranspiration in West Papua indicated by ME = 0.66 mm/day, RMSE = 0.94 mm/day, RB = 0.27, and MBF = 0.81. Therefore, MODIS global evapotranspiration can be used as an alternative solution for providing evapotranspiration data in West Papua with a cost-effective.

Revegetation of Critical Land with Gaharu (Aquilaria malaccensis) under Various Ameliorants Application

Rehabilitation of post-mining limestone soils is often a challenge due to a lack of nutrients and poor soil humus. The research aims to study the effect of various ameliorants on soil chemical properties, growth, and P uptake of gaharu plant (Aquilaria malaccensis) in post-mining limestone soil for revegetation of critical land. The research was conducted in a Completely Randomized Design with three replications. The treatments were P0 (Control, without ameliorant); P1 (Humic Acid, HA, 4 kg ha-1 ); P2 (Phosphate Rocks, PR, 350 kg ha-1 ); P3 (Vesicular Arbuscular Mycorrhizal Fungi, AMF, 500 spores plant-1 ); P4 (HA+AMF); P5 (PR+AMF); and P6 (HA+PR+AMF). Data were analyzed using ANOVA at 95% confidence level and continued with the LSD test. The use of various types of ameliorants (HA, RP, and AMF) significantly increased root length, root volume, wet and dry weight of roots, shoot wet and dry weight, and P uptake of gaharu tree. The best ameliorant in increasing gaharu tree growth was AMF (P3) treatment, and AMF combined with HA (P4) treatment. Thus, for revegetation of critical land, especially post-mining limestone land, using gaharu tree requires HA and AMF inoculation.

Dynamics of Soil Moisture under Different Water Levels and Various Dosages of Organic Fertilizer

The study aimed to determine the dynamics of soil moisture in various standing water levels and dosages of organic fertilizer. The experiment was arranged in a Completely Randomized Block Design (CRBD) with a 3 × 3 factorial treatment in 3 replicates. The first factor was 3 different water levels, namely 10 cm (T1), 20 cm (T2), and 30 cm (T3). The second factor was 3 levels of dosages of organic fertilizer, namely 0 g pot-1(P1), 35 g pot-1 (P2), and 70 g pot-1 (P3). The highest of soil moisture was obtained in the 10 cm water levels and 70 g organic fertilizer (T1P3) and the lowest in the 30 cm water levels and without organic fertilizer (T3P1). The highest infiltration rate was obtained in the 30 cm water levels and 70 g pot-1 organic fertilizer (T3P3), the 30 cm water levels and 35 g pot-1 organic fertilizer (T3P2), the 20 cm water levels and 70 g pot-1 organic fertilizer (T2P3), and the lowest in the combination of the 10 cm water levels and without organic fertilizer (T1P1). The highest capillary rate was obtained in the combination of the 30 cm water levels and 70 g organic fertilizer (T3P3) and the lowest in the combination of the 30 cm water levels and without organic fertilizer (T3P1).

Soil Quality Engineering Using Vermicompost and its Effect on the Corn (Zea mays L.) Production in Coastal Area

The low quality of Entisol is caused by low availability of nitrogen, phosphorus, and potassium as well as low soil pH, so the addition of vermicompost is necessary. The purpose of this study was to determine the effect of vermicompost application on soil quality and to obtain the highest vermicompost dosage on the availability of nutrients such as N, P, K, and the yield of corn. The field experiment used a Randomized Completely Block Design (RCBD) with 7 dosages of vermicompost and three replications. The treatments were V0 = 0; V1 = 5; V2 = 10; V3 = 15; V4 = 20; V5 = 25; V6 = 30 Mg ha-1. Variables observed consisted of 1) initial soil and vermicompost characterization analysis, 2) soil analysis and N, P, and K content in leaves, and yield of corn. The results showed that Entisol was classified as low quality; however, vermicompost quality complied with the requirements of quality organic fertilizer. The experiment also indicated that the highest pH of Entisol (5.31) and K content in corn leaves (2.12%) were obtained at a dose of vermicompost 25 Mg ha-1. Meanwhile, the highest weight of husked corn cobs (415.55 g plant-1) and weight of unhusked corn cob (351.11 g plant-1) were obtained at a vermicompost dose of 15 Mg ha-1.

Study on Nutrient Balances of Newly Developed Lowland Rice Fields at Kleseleon Village, Malaka District, Nusa Tenggara Timur

The land allocated for newly opened lowland rice can be from ultisols, oxisols, inceptisols, and potential acid sulfate soils. The study was aimed to evaluate nitrogen (N), phosphorous (P), and potassium (K) inputs – outputs of newly developed lowland rice under different treatments and to validate the N, P, and K recommended applications rate according to N, P, and K balances. The study was conducted in Kleseleon village, Malaka District. Five treatments were tested namely T0: farmers practices, T1: NPK at recommendation rate + Rice straw compost, T2: NPK at recommendation rate + Smart + Rice straw compost, T3: ¾ NPK at recommendation rate + Smart + Rice straw compost, and T4: NPK at recommendation rate + Smart + Rice straw compost. The treatments were arranged in a randomized complete block design with three replications. The nutrient balances were constructed according to the difference between nutrient inputs and losses. The results indicated that there were surplus N, P, and K across the treatments and more than adequate to replace N, P, and K removed by harvest products. The suggested N, P, and K application rates were 100 kg urea, 100 kg SP-36, and 100 kg KCl with the addition of compost 3 Mg ha-1 season-1.

The Diversity of Mycorrhiza Arbuscular Fungi in Several Types of Peatland Utilization in Sungai Asam Village Kubu Raya District

The purpose of this study was to determine the diversity of FMA from the rhizosphere of cassava, corn, taro, ginger, kale, pineapple which was cultivated in the Sungai Asam peatland by using a corn plant host. This research was conducted at the Soil Biology and Biotechnology Laboratory of the Faculty of Agriculture and plastic houses in the Universitas Tanjungpura Faculty of Agriculture’s experimental garden. The study was conducted from August 2nd to October 21st, 2018. The procedure was done by taking soil and root samples from cassava, corn, taro, and peanut rhizosphere cultivated on peatland. A sampling of soil and roots in each rhizosphere was carried out at 4 observation points as replication with a depth of 0-20 cm and a diameter of 20 cm and then put into a plastic bag and labeled. Then, the soil samples taken were used for microscopic analysis (extraction and identification) and were analyzed to determine their chemical properties. Root samples were colorized to determine the percentage of colonization, and corns were used to cultivate. Furthermore, extraction and identification of spores were carried out using the same technique as extraction and identification of soil samples. The variables observed included the percentage of root colonization, spore density, and spore diversity. The FMA diversity of the 6 types of peatland utilization from the rhizosphere of cassava, corn, taro, ginger, pineapple, and kale in the Sungai Asam village before and after trapping showed an increase in the number of spores, diversity of FMA”while the percentage value of root colonization was varied. Moreover, the number of spores increased from around 36 - 52 spores per 50 g of soil to 61 - 178 spores per 50 g of soil. The diversity of spore types increased from 10 types of Glomus, 1 type of Gigaspora, and 4 types of Acaulospora to 13 types of Glomus, 3 types of Gigaspora, and 5 types of Acaulospora. The highest percentage of infected roots before trapping ranged from 48.89% - 78.48% and after trapping ranged from 78.89% - 94.80%.

Adaptation of New Rice High Yielding Varieties on New Constructed Irrigated Rice Field Affected by Sea Water Intrusion in West Tanjung Jabung District, Jambi

Assessment adaptation of several new superior rice varieties on new rice fields affected by seawater intrusion was carried out in Tungkal Ilir Subdistrict, West Tanjung Jabung District, from April to October 2018. The study applied randomized block designs (RBD) with four replications. The treatments consisted of four new rice high yielding varities suitable for tidal/swamps areas namely Inpara 3, Inpara 8, Inpara 9, and Inpari 34 Salin Agritan, and one local rice variety (Londo) as control. Three stems seedlings per clump were planted at the age of 21-25 days, using a 4:1 Legowo planting system. Fertilizer application consisted of basic fertilizer (1.0 Mg ha-1 of lime, 2.5 Mg ha-1 of manure, and 75 kg ha-1 of urea) and supplementary fertilizer (SP-36 150 kg ha-1 and KCl 125 kg ha-1),. Urea supplementation is given based on observations with a leaf color chart (LCC). The results of the study showed that the four new rice HYVs were more adapted as compared to the local rice variety. The performance of the tested new rice HYVs showed quite a good growth appearance and productivity. The highest production was obtained in Inpari 34 Salin Agritan variety 2.85 Mg ha-1, while Inpara 3, Inpara 8, and Inpara 9 ranged between 2.0 and 2.1 Mg ha-1, while the local variety’s productivity was 1.9 Mg ha-1.