Search

This study aims to compare the soil quality indexing model by adding and weighting the soil under different land uses and slope positions on the southwest slope of Mount Merapi, Indonesia. Soil sampling was carried out based on a landscape analysis divided into four geomorphological units (slopes): upper, middle, lower and foot slopes. The research design was nested where the soil sample was located (surface soil 0-30 cm). Based on the research results, soil quality indices (SQI) of forest on the upper slopes is very high. SQI of dry fields on the middle, lower and foot slopes is low to medium. SQI of mixed gardens on the middle and lower slopes is low to medium. SQI of snake fruit land on the middle, lower and foot slopes is medium to high. SQI of grassland on the lower slopes is medium to high, and SQI of paddy fields on the foot slopes is medium to high. Weighted soil quality index (SQIw) has a higher correlation (R2 = 0.90) and can predict soil quality better than the adding soil quality index (SQIa) model (R2 = 0.76). Indicators that most influence soil quality are the percentage of sand, total N, C-POM, C-Min, pH, and aggregate stability, that indicators are entirely influenced by organic matter, site-specific management to maintain SQI by maintaining organic matter. The selected indicators in this study can be used to determine the SQI in similar areas.

Edamame soybean (Glycine max (L.) Merr.) cultivation in phosphorus-limited Andisols presents a formidable challenge due to restricted phosphorus availability despite high phosphorus retention. Unlocking the full potential of this crop demands innovative solutions. This study delves into the transformative effects of biochar and phosphorus fertilizer, individually and synergistically, on edamame soybean growth in Andisols. Employing a randomized complete block design, researchers investigate three types of biochar (B0: control, B1: biochar pellets, B2: biochar powder) and four phosphorus fertilizer rates (P0: control, P1: 27 kg ha-1 P2O5, P2: 54 kg ha-1 P2O5, P3: 81 kg ha-1 P2O5). The bamboo-derived biochar was produced using the Kon-tiki method at ±500 °C. The study reveals no significant interaction between biochar and phosphorus fertilizer. Individually, treatments with B1, B2, and phosphorus fertilizers significantly enhance ammonium, nitrate, and phosphorus availability compared to B0 and P0. Biochar-induced modifications improve phosphorus and nitrogen absorption by roots, resulting in increased shoot dry weight and the root/shoot ratio. However, the number of leaves is solely influenced by phosphorus fertilizer treatment. Additionally, both biochar and phosphorus fertilizers contribute to nitrate reductase activity, root volume, an increased number of pods per plant and higher protein content in edamame soybeans. B2 outperforms B1 and high P3 intensifies this effect, improving nutrient uptake and yield. In summary, biochar and phosphorus fertilizers demonstrate significant potential to revolutionize edamame soybean cultivation in phosphorus-limited Andisols, optimizing pod number per plant and enhancing quality with elevated protein content.

The type of vegetation and soil organic matter affect the carbon fraction, nitrogen fraction and soil carbon stocks that contribute to the global carbon cycle. Therefore, the calculation of the composition of the fractions in different land covers is very important as a potential indicator of the effect of land management practices on soil organic carbon dynamics and supports the reduction of carbon dioxide (CO2) and soil carbon storage. This research aimed to determine the composition of the carbon fraction, nitrogen fraction and soil carbon stock in different land cover. There were six types of land cover with vegetations of 10-year-old bamboo, 30-year-old bamboo, 50-year-old bamboo, bulrush, a mixture of brushwood and bulrush, and a mixture of Albizia falcataria and brushwood, each of which was sampled three times. Soil samples were used to determine microbial biomass, particulate organic, humic acid, fulvic acid and soil carbon stock. The six land cover types showed significant differences in all fractions and soil carbon stocks. Fifty-year-old bamboo vegetation has the highest carbon storage of 0.029 g g-1 soil. The stable carbon fraction, in the form of humic acid and fulvic acid, in 50-year-old bamboo vegetation is more excellent than that in other vegetation. This study shows that 50-year-old bamboo vegetation has the potential to sequester carbon and store carbon in forms that decompose slowly, namely humic acid and fulvic acid, in the soil for a longer period.

This study investigates the impact of boron fertilizer on physiological activities of cocoa trees, specifically focusing on boron content, nitrogen content, nitrate reductase activity, chlorophyll content, and photosynthesis rate in cocoa plant leaves. This research was arranged in a randomized complete block design with two treatment factors, which were the type of boron fertilizer application (soil and foliar fertilizer), and the dose of boron fertilizer (1.5, 3, 4.5, and 6 g plant−1 with 0 g plant−1 as a control). Data were then analyzed for variance differences (ANOVA) with α = 5%, followed by the Tukey test, and contrast orthogonal for comparing treated and control plants. The results showed that the dose of boron fertilizer and the type of fertilizer application used have a significant effect on the physiological activity of the cocoa plant. The dose of boron with soil application affects physiological activity in a linear pattern where each additional dose of boron will increase the activity of nitrate reductase, chlorophyll content, and photosynthetic rate. The dose of boron with foliar application affects physiological activity in a quadratic pattern, where the dose of boron in the range of 3 g plant−1 is the optimum dose that gives maximum results on nitrate reductase activity, chlorophyll content, and photosynthetic rate in the cocoa leaves. Therefore, it is considered that the application of boron fertilizer at a dose of 3 g plants−1 with the foliar application is more efficient in increasing physiological activity compared to the dose of boron with soil application.

Biji kakao merupakan bahan utama pembuatan berbagai produk makanan, minuman dan obat obatan, hal tersebut menyebabkan permintaan kakao terus meningkat. Namun demikian peningkatan kebutuhan tersebut tidak diimbangi dengan peningkatan produksi di tingkat produsen. Indonesia sebagai salah satu produsen terbesar kakao dunia justru mengalami penurunan produksi dan kualitas akibatnya volume eksport terus mengalami penyusutan. Salah satu penyebab rendahnya produksi dan kualitas biji adalah kesuburan tanah. tanaman kakao merupakan tanaman yang sangat peka terhadap ketersediaan unsur hara. Berdasarkan hal tersebut maka tujuan dari penelitian ini adalah untuk mengetahui pengaruh status kesuburan tanah terhadap produksi dan kualitas biji beberapa klon kakao. Penelitian ini dilaksanakan pada Bulan June 2017 sampai bulan Oktober 2018 bertempat Di kebun kakao milik PT Pagilaran Unit Segayung Utara yang berlokasi di Desa Simbangjati, Tulis Kabupaten Batang Jawa Tengah. Penelitian dirancang menggunakan rancangan tersarang (Nested Design) dengan tiga klon (RCC 70, RCC 71 dan KKM 22) bersarang pada dua Status kesuburan tanah. Status kesuburan tanah didasarkan pada level ketersediaan unsur hara N,P,K dan B. Paramemeter yang diamati adalah karakteristik tanah, karakter fisiologis yang meliputi kadar klorofil daun, Laju fotosintesis, kandungan CO2 daun, kandungan H2O daun, Laju transpirasi dan Lebar bukaan Stomata, Komponen hasil meliputi berat biji perbuah, jumlah biji perbuah, berat biji perpohon, jumlah buah perpohon dan produksi per hektar. Serta komponen kualitas yang meliputi kadar lemak, kadar protein dan bean count. Hasil menunjukkan bahwa status kesuburan tanah tinggi memperlihatkan kadar klorofil, laju fosintesis , kadar CO2 dan H2O daun lebih tinggi yang menyebabkan produksi dan mutu biji (bean count dan kadar lemak) lebih tinggi.

Biochar quality is influenced by the type of its raw material and pyrolysis temperature. Nevertheless, the quality criteria of biochar as a nutrient carrier remain unanswered. This study aimed to find the chemical properties, micromorphology, and optimum pyrolysis temperature from various agricultural wastes to obtain good biochar as a nutrient carrier. This experiment was conducted at three level temperatures: 400, 500, and 600°C, and the raw materials were coconut shells, oil palm shells, and corn stalks. The chemical and physical properties of biochar were: pH-H2O, OC, CEC, total N, P, K, Mg, Ca, and Na, ash, functional groups, amorphous carbon, morphology, and SSA. The results show that the coconut shells and oil palm shells biochars contained high levels of N-total and the chain-C aromatic, and the pore structure was solid and regular. Corn stalks biochar containing ash is high, and C-aromatic is low and fragile. Increased temperature of pyrolysis produced well-crystallized minerals. It is concluded that 500°C is the optimum temperature for oil palm shells pyrolysis resulting in biochar with the highest C-aromatic structure and arrangement of pores which are strong, regular and uniform, and high stability, but the nutrient content was low.

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.

Potato self-sufficiency in Indonesia faces three main problems: rising air temperatures, limited availability of low-temperature land suitable for potato cultivation, and lack of high-temperature tolerant potato varieties. Therefore, it is necessary to identify the tolerance of potato variety to high-temperature. This research was conducted in two locations: the optimum temperature location and the high-temperature location, using nine varieties, are Agria, Andina, Amabile, Cingkariang, Granola L, Granola K, Margahayu, Olympus, and Tedjo-MZ. The study design uses a split plot with three replications. Differences in temperature as the main plot and varieties as subplots. Parameters observed were air temperature, growth, and yield of potato tubers. The analysis carried out were the Stress Sensitivity Index (SSI), Stress Tolerance Index (STI), Yield Stability Index (YSI), and Cluster Analysis. The results showed that there were no tolerant to high-temperature varieties. Based on the STI, only Olympus was a medium tolerant of high temperatures. Based on the Stress Sensitivity Index (SSI), four varieties are moderately susceptible to high temperatures (Olympus, Andina, Cingkariang, and Margahayu). The YSI analysis shows the same results as the SSI. The cluster analysis results showed harmony between the results of the stress index analysis and cluster analysis. Nine varieties had a high similarity (87.3%), meaning that all varieties had the same characteristics and less tolerance to high temperatures. Olympus was the more tolerant variety to high temperatures, followed by Andina, Cingkariang, and Margahayu. The four varieties consider promising potato lines in high-temperature areas.

The expansive ability of soil causes a series of problems in various sectors. The dominance of smectite clay minerals significantly affects expansive ability because they have an unstable interlayer structure. Cation intercalation and calcination is a treatment method that can increase the stability of the clay interlayer structure. This research investigated the effects of intercalation cations and calcination treatment on the swelling ability and cracking properties in the clay from vertisols; the cations used for intercalation were aluminum and iron. The intercalation tested doses were based on the equivalent weight of 0x, 0.5x, and 1x cation exchange capacity (CEC) clay value. The calcination treatments used were 200°C, 300°C, and no calcination. Each treatment interaction was repeated three times. Parameters observed were the total area, average crack width, average lump area, total number of lumps, moisture content, swelling volume, and pH after treatment. The results showed that each treatment had a significant effect. Clay with an Al intercalation dose of 1x CEC without calcination treatment had the highest total area after drying, which was 41.035 cm2; the lowest average crack width was 0.153 cm, and the smallest swelling volume was 3.6 cm3. In contrast, the clay without intercalation and calcination treatments had a swelling volume up to 10 cm3 on the 7th day. The clay with an Al intercalation dose of 1x CEC with 200°C calcination exhibited the best results in reducing the expansive clay ability and can be used as a guideline for further testing to reduce the soil’s expansive ability.

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, Gadjah Mada University. 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 2 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 3 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.

The need of nitrogen (N), phosphate (P) and potassium (K) nutrient in oil palm nursery are usually fulfilled with synthetic chemical fertilizers such as NPK fertilizer. The application of NPK fertilizer can cause the soil to become hard due to the accumulation of the residue left on the ground. Cow manure is able to substitute NPK fertilizer based on the chemical status of the soil. This study aimed at analyzing the effect of NPK fertilizer substitution with cow manure on the growth of oil palm seedlings in the pre-nurseries and main nurseries. The experiment was conducted from February to September 2018 in the Banguntapan research and experimental field, Faculty of Agriculture, Universitas Gadjah Mada. The experiment applied the Randomized Complete Block Design (RCBD) with one factor and six blocks as replications. The factors were subtitution using the replacement series method with five levels of doses, 100% NPK, 75% NPK + 25% cow manure, 50% NPK + 50% cow manure, 25% NPK + 75% cow manure and 100% cow manure. The observed parameter variables were root lenght, root area, hump diameter, leaf area, the number of leaves, plant height and plant dry matter. The use of 25% NPK substitute with 75% organic material was the best result in increasing the growth performance of oil palm seddlings in pre-nursery and main nursery.

The low yield of rice in thick peat can be overcome by provisioning complete nutrients. Various efforts have been made to increase the productivity of Indonesian peatlands, one of which is by adding salted fish waste and cow manure. This research was carried out on a plastic house scale from October 2017 to January 15, 2018, in Pelalawan District, Pelalawan Regency, Riau. This research was arranged in a Completely Randomized Design (CRD), consisting of eight treatments, namely L0 = Control, L1 = 1.5 ton.ha-1 of fish waste, L2 = 2.25 ton.ha-1 of fish waste, L3 = 7 tons/ha of cow manure, L4 = 15 ton.ha-1 of cow manure, L5 = 1.5 ton.ha-1 of fish waste + 7 ton.ha-1 of cow manure, L6 = 1.5 ton.ha-1 of fish waste + 15 ton.ha-1 of cow manure, L7 = 2. 25 ton.ha-1 of fish waste + 7 ton.ha-1 of cow manure, and L8 = 2.25 ton.ha-1 of fish waste + 15 ton.ha-1 of cow manure. The results showed that the application of cow manure and salted fish waste could increase soil pH, total NPK, and NPK uptake. The application of 2.25 tons/ha of fish waste and 15 tons/ha of cow manure resulted the best results in soil pH, total NPK, and NPK uptake, therefore it is recommended for the cultivation of lowland rice on peat soil.

The main constraint in the extensification of maize on the dry land of acid soil is the low availability of P in soil. This study aimed to determine the effect and the optimal dose of humic acid on the growth and yield of maize on acid soil. This research was conducted from February to May 2017 at Tri Dharma Field Laboratory, Faculty of Agriculture, Gadjah Mada University. Acid soil with low P availability used was from sub-district Cigudeg and Jasinga, West Java. The research was arranged in Randomized Complete Block Design (RCBD) with 2 factors. The first factor was maize cultivar, namely Bisi 2 and Pioneer 35. The second factor was the rate of humic acid and NPK fertilizer, consisting of 0 kg.ha-1 (without) NPK and 0% (without) humic acid, NPK + 0% (without) humic acid, NPK + 5% humic acid, NPK + 10% humic acid, and NPK + 15% humic acid. NPK fertilizer applied was NPK 16:16:16 at a dose of 350 kg.ha-1. The results showed that humic acid application on acid soil increased C-humic content in the soil, soil P availability, total dry weight of the plant, and kernel dry weight at harvest (15 weeks after planting). The increase in soil P availability did not improve the plant growth but increased the accumulation of plant biomass. The application of humic acid at 15% (52.5 kg.ha-1) combined with NPK fertilizer on acid soil significantly increased total dry weight of plant and kernel dry weight up to 13.14% and 21.81%, respectively, thus, it is recommended for maize cultivation on acid soil.

Applying volcanic ash as planting media has to cope with several constrains: it quickly became sediment and hardened when exposed to water. One of the efforts to improve its physical condition is by utilizing biochar, which is one of amendment materials that can improve the soil quality. This study used vertical column container made from PVC to enable vertical plant arrangement. Volcanic ash requires additional nutrient intake from organic fertilizer such as urban waste compost. The objective of this study was to identify the proper dose combination of volcanic ash, biochar, urban waste compost fertilizer and column population per m2 to sustain the growth of curly lettuce in vertical cropping system, as well as the water use efficiency. This study was designed by using the Completely Randomized Design (CRD) Factorial with three factors. The first, second and third factors consisted of Biochar M1, M2 and M3 (25; 33; and 50 %), compost fertilizer doses of K1, K2, and K3 (25; 33; and 50 %), and column density of P1, P2 and P3 (4 columns/m2, 3 columns/m2 and 2 columns/m2), respectively. The total combination was 3 x 3 x 3 and each was repeated 3 times. Resulted data of this study consisted of growth and crops and analyzed by using the Analysis of Variance and continued with the HSD Tukey 5% Test (Honest significant deference). The water use efficiency (g/kg) can be formulated as the production of dry material per total water during the cultivation season (g/kg). Results of this study showed the highest fresh consumption result was obtained from treatment M3K3 in 556 g/column (comparison of volcanic ash, charcoal husk and compost = 25 : 25 : 50 %) and the best water-use efficiency was 2.30 g/kg.

Humic acids containing carboxyl and hydroxyl groups that have the ability to cover the P adsorption site in Typic Hapludults. Molybdate has similarity behaviour with phosphate in theacid soils. Research aim was to study the effects of molybdate and humic acid to the kinetics of phosphate adsorption in Typic Hapludults of Cigudeg, Bogor. Important of kinetics is to get accuration of materials transport, to control influence on anion mobility, that the assessment is needed for the efficient application of Mo and P. Aplication humic acid and molybdate as competitor anion of phosphate was conducted with combination of humic acid and Mo concentration as double anions. Many models describe the kinetics for the adsorption of phosphate by soils i.e. zero order, first order, second order, and Elovich. As ststistically, there was not interaction of humic acid and molybdate on P adsorption. Application of humic acid with rate of 100 mg.L-1 was not effective decrease P adsorption in Typic Hapludults. It was due to the pH of the adsorption system that get near to its pKa of carboxyl gruop about 5. Meanwhile aplication 2 and 5 mmol.L-1 of molybdate significantly decrease of P adsorption. The second order kinetics models apropriate to the adsorptionof P in the Typic Hapludults of Cigudeg, with determination coefficients value (R2) of 0.999-1 and standard error value (SE) of 0.001–0.011.The results suggest that the molybdate as competitor anion affected the kinetics for the adsorption of phosphate due to the charge of molybdate.

Different weeding frequencies (WFs)―0WF, 2WF, 4WF, 6WF, and 8WF―were adopted in an organic rice field to investigate their influence on weed types, rice and weed biomass, rice tiller and weed number, N concentration, and N uptake. The study field was located in Tsuruoka, Yamagata, Japan. Rice (cv. Sasanishiki) was planted from May to September 2019, and all weeding events were carried out until 49 days after transplantation (DAT) using a rotary weeder. Rice and weed samples were collected at 60, 88, and 110 DAT. Echinochloa crus-galli (E. crus-galli), Schoenoplectus juncoides, and Monochoria vaginalis (Burm. f.) were the most commonly found weeds. High weed diversity was observed at both 6WF and 8WF, E. crus-galli was the dominant weed at 0WF. Compared to 0WF, 2WF displayed a significantly decreased weed biomass. However, at 8WF, the weed biomass was reduced by 79.0%, the rice biomass was increased by 277%, and the rice tiller number was almost three times higher than that at 0WF and 110 DAT. Compared to 0WF, a significantly increased rice N uptake was observed at 4WF, and rice N uptakes achieved at 6WF and 8WF were two and four times higher than those at 0WF, respectively. Higher weeding frequencies provide notable benefits in suppressing weeds and supporting rice growth, especially in N uptake competition with weeds.

Industri gula Indonesia berada di bawah tekanan untuk meminimalkan kehilangan nutrisi off-farm dan mengurangi seluruh biaya produksi. Saprodi pupuk menyerap biaya produksi 65% dari total biaya. Salah satu upaya yang dapat dilakukan adalah penerapan rekomendasi pupuk spesifik berdasarkan analisis tanah. Penelitian ini bertujuan untuk mengelompokkan petak Status Hara N Total, P-Tersedia, K-Tertukar dan cluster rekomendasi pemupukan tanaman tebu (Saccharum officinarum Linn.) di kebun Unit Usaha PG. Djatiroto, Lumajang melalui pemetaan. Analisis dilakukan terhadap 48 sampel, dengan 1 sampel mewakili petak 6,25 ha. Pengelompokan petak berdasarkan peubah konsentrasi N Total, P-Tersedia, K-Tertukar dilakukan dengan metode Hierarchical cluster Analysis dan Sistem Informasi Geografis (GIS) mulai dari bulan Januari sampai Mei 2014. Hasil analisis mendapatkan 5 kelompok area rekomendasi pemupukan. Satu kelompok (cluster 3) yang terdiri dari satu petak dengan rekomendasi 160 kg N/ha, 90 kg P2O5/ha,145 kg K2O/ha; cluster 1 yang terdiri dari 29 petak dengan rekomendasi 160 kg N/ha, 90 kg P2O5/ha, 175 kg K2O/ha; cluster 2 yang terdiri dari 7 petak dengan rekomendasi 120 kg N/ha, 90 kg P2O5/ha, 175 kg K2O/ha, cluster 4 yang terdiri dari 23 petak dengan rekomendasi 160 kg N/ha, 135 kg P2O5/ha, 175 kg K2O/ha; cluster 5 yang terdiri dari 6 petak dengan rekomendasi 120 kg N/ha, 135 kg P2O5/ha, 175 kg K2O/ha.