Solid Organic Fertilizer Research Articles

A bioreactor and nutrient balancing approach for the conversion of solid organic fertilizers to liquid nitrate-rich fertilizers: Mineralization and nitrification performance complemented with economic aspects

Due to the high water- and nutrient-use efficiency, hydroponic cultivation is increasingly vital in progressing to environment-friendly food production. To further alleviate the environmental impacts of synthetic fertilizer production, the use of recovered nutrients should be encouraged in horticulture and agriculture at large. Solid organic fertilizers can largely contribute to this, yet their physical and chemical nature impedes application in hydroponics. This study proposes a bioreactor for mineralization and nitrification followed by a supplementation step for limiting macronutrients to produce nitrate-based solutions from solid fertilizers, here based on a novel microbial fertilizer. Batch tests showed that aerobic conversions at 35 °C could realize a nitrate (NO₃−-N) production efficiency above 90% and a maximum rate of 59 mg N L−1 d−1. In the subsequent bioreactor test, nitrate production efficiencies were lower (44–51%), yet rates were higher (175–212 mg N L−1 d−1). Calcium and magnesium hydroxide were compared to control the bioreactor pH at 6.0 ± 0.2, while also providing macronutrients for plant production. A mass balance estimation to mimic the Hoagland nutrient solution showed that 92.7% of the NO₃−-N in the Ca(OH)₂ scenario could be organically sourced, while this was only 37.4% in the Mg(OH)₂ scenario. Besides, carbon dioxide (CO₂) generated in the bioreactor can be used for greenhouse carbon fertilization to save operational expenditure (OPEX). An estimation of the total OPEX showed that the production of a nutrient solution from solid organic fertilizers can be cost competitive compared to using commercially available liquid inorganic fertilizer solutions.

Utilization of tourmaline stone as a fertilizer in medicinal plant verticulture

Citizen activities towards the community which will be carried out by non-people groups in Jati Village, Jaten District, Karanganyar Regency. The location is classified as Peri-Urban area, where agricultural land has been largely over the function of land, the number of people who do the transfer of professions from the agricultural sector to the industry, and the home yard environment that can be expanded again. However, the existing yard can still be optimized to do household activities, namely to cultivate verticulture medicinal plants. The existence of medicinal plants in the home environment itself will be a process for people to live a healthy life that is cheap and natural. This community program will be carried out by testing and mica the efficacy of tourmaline stone as a plant material on several types of plants in verticulture media that become two separates. The first part will be applied solid organic fertilizer plant fertilizer that is proceed independently by the residents, and the second will be applied tourmaline stone into plant fertilizing material. It is toothed for the direct effect of tourmaline stone in fertilizing plants when compared to the ability of solid organic fertilizers which are processed by the residents themselves.

Utilization of Dried Leaf Litter as Organic Fertilizer in Talang Ilir Hamlet, Sukamoro Village, Banyuasin Regency, South Sumatra

None of the dried plant leaves in Sukamoro Village use them as organic fertilizer, instead, they are piled up as garbage and then burned. This dry leaf litter is a problem and is considered to be very polluting to the nature conservation disturbance. If the dry leaf litter can be processed into solid organic fertilizer, it can reduce environmental pollution and is very useful in increasing plant growth and production. This organic fertilizer is easy to make and raw materials are available in the Sukamoro village. This service aims to invite the people of Dusun Talang Ilir to use dry leaf litter as organic fertilizer. The counseling had been held in Talang Ilir Hamlet RT 03 RW 01 Sukamoro Subdistrict, Talang Kelapa District, Banyuasin Regency, South Sumatra from February 8 to March 8, 2021, with KKN Class 25 students of 2021. The method used was the socialization of making organic fertilizer using dry leaf litter around the environment. The people of Talang Ilir Hamlet RT 03 RW 01 Sukammoro Village want to try making organic fertilizers from dry leaf litter.

EFFECT OF SOLID AND LIQUID ORGANIC FERTILIZER ON GROWTH, YIELD AND YIELD COMPONENTS OF ROSSELLE (Hibiscus sabdariffa L.) IN THE NIGERIAN SAVANNAH

The Study was conducted to evaluate the effect of solid and liquid organic fertilizer on growth and yield of rosselle in 2016 cropping season at Institute of Agricultural Reserve Zaria, Samaru (11011’N 07038E and 686m) and Institute of Horticultural Research Farm Bagauda (12000’N 8031”Em 488m) in Northern Guinea Savannah and Sudan Savannah Ecological Zones of above sea level Nigeria. Treatments consisted of four levels of solid poultry manure (0.0, 1.0, 2.0 and 3.0) tons/ha and five levels of liquid organic manure from Grand Total Organic Fertilizer Limited (0.0, 0.5, 1.0, 1.5 and 2.9) litres/ha, which were factorially combined in a randomized complete block design (RCBD) and replicated three times. Data on growth parameter were collected on plant height (cm), plant dry weight (g), leaf Area index crop growth rate (CGR) Relative Growth Rate (RGR) and Net assimilation rate (NAR) while data on yield parameters like number of calyx per pant, 100 seed weight (g) and calyx yield per hectare kg/ha were collected. Results showed that plant height, plant dry weight(g), 100 seed weight(g) and calyx dry yield kg/ha had a significant increase with application of 2.0 litres/ha of liquid fertilizer than other rates. While application of solid poultry manure at 3.0ton/ha significantly increases plant height, net assimilation rate, leaf area index and calyx dry weight when compared with other rates. From the results obtained, the combination of 2.0 litres/ha liquid organic fertilizer and 3.0 ton/ha solid poultry manure produce the highest calyx yield at both location.

Daur Ulang Kombinasi Limbah Pertanian menjadi Kompos Berkualitas

Waste Population in Indonesia According to the Ministry of Environment and Forestry (2015), the amount of landfill has reached 175,000 tonnes/day or the equivalent of 64 million tonnes/year. Utilization of the waste is used as solid organic fertilizer which can be applied to soil to increase crop production. The research used waste from cocopeat, banana fronds and maggot pupae. This study aims to determine the characteristics of solid organic fertilizers made from cocopeat waste, banana fronds and maggot pupae. In addition, there are materials, namely EM4 as microorganisms, molasses as a food source for microorganisms and water to regulate humidity during the composting process. Each parameter will be tested and compared with the minimum technical requirements for solid organic fertilizer contained in Permentan/SR.140/10/2011. The results showed that solid organic fertilizers made from cocopeat, banana fronds and maggot pupae were of the same quality as the minimum technical requirements, namely solid organic fertilizer. includes parameters C/N ratio, pH, water content and (N+P205+K20). The results of the best treatment research on sample A (100 ml/ EM4) meet the standards because above 4% the content of the nitrogen presentation is 4.72%, phospor (P205) is 4.40% while the potassium content is below the standard for making solid organic fertilizer with a percentage of 3.96% for the variation of 100 ml/EM4, 23.51% C-Organic has met the minimum standard, namely 15-25% and C/N ratio of 4.98% is below the standard, which is below 5%. Keywords : Banana fronds, Cocopeat, EM4, Maggot pupae, Waste quality

Characterization of composted organic solid fertilizer and fermented liquid fertilizer produced from the urban organic solid waste in Paipa, Boyacá, Colombia

Purpose Urban organic solid waste (UOSW) has great potential to be transformed into solid and liquid organic fertilizers, thus avoiding its accumulation in landfills and reducing the environmental impact caused by the generation of gases and leachates. Therefore, the purpose of this research was to study the management of the UOSW in the municipality of Paipa as raw material for obtaining solid organic fertilizer through composting and a liquid fertilizer through fermentation. Method The UOSW of Paipa was combined with inorganic salts such as carbonates, phosphates, sulfates and source of carbohydrates to enrich its bacterial load and chemical composition. The content of essential nutrients that contribute to good soil-plant synergy, heavy metals and pathogenic microorganisms in the primary and final material were determined. Results The experiment showed a high COO load, between 24-35%, and similar values in organic N content in the primary materials. Heavy metals were found below the minimum allowed by the CTS 5167 of 2011 for the organic solid residue, and no pathogenic microorganisms were found. Composting and fermentation processes improved the physical-chemical properties of the materials; however, the liquid mineral organic fertilizer did not comply with the established parameters, while the solid one was in compliance with the requirements. Conclusion After a period of 4 months, the study showed that solid UOSW from the municipality of Paipa can be used as a potential source for producing organic fertilizers by adding nutrients in mineral forms, complying with the nutrient requirements for plants and soil feeding organisms.

Increasing Productivity and Biomass of Corn Plants Toward Grant Organic Fertilizer and Liquid Organic Fertilizer

The use of corn as animal feed focuses on the use of biomass as feed for ruminants and shelled corn as poultry feed. One of the efforts to increase biomass and protein in corn is by applying fertilizer, namely organic fertilizer. Therefore, the purpose of this study is to determine the effectiveness of using granular and solid organic fertilizers and to determine the best concentration of both types of fertilizers in increasing maize productivity and biomass. The study was designed using a Split Plot Design with an environmental design, namely a Randomized Block Design (RAK). The main plot is organic fertilizer granule petroganik consisting of 3 levels, namely control (G0), 1000 kg ha-1 (G1) and 2000 kg ha-1 (G2). The sub-plots were Biotani liquid organic fertilizer which consisted of 4 levels, namely control (P0), 2 cc/L (P1). 4 cc/L (P2), 6 cc/L (P3). The treatment of granule and liquid organic fertilizer increased the growth potential and productivity of maize. The optimal treatment of granulated organic fertilizer is G1 treatment. Meanwhile, the best treatment for liquid organic fertilizer is P1 treatment. The combination of G1P1 is still recommended even though there is no interaction between granule and liquid organic treatments.

Effects of Liquid and Solid Organic Fertilizer from Urine and Feces of Cow on Rice Production

This study aims to determine the effect of Liquid and Solid Organic fertilizers from Urine and feces of Cows on Rice Production. It was conducted on March-July, 2019 in Siti Mulyo village, Piyungan sub-district, and Bawuran village, Pleret sub-district, Bantul regency, Indonesia. Furthermore, about 74 farmers were included and were divided into three differing patterns (A, B, and C) of 16, 30 28 respectively. Farmers in A and B conducted solid and liquid organic fertilizer application methods for 4 ton/ha and 3.2 liter/ha. The rice planting system of A was similar Tajarwo 4:1 while B appeared as squares (25 cm × 25 cm). Pattern C farmers used fertilizer and rice planting systems according to their habits. The variables observed were plant height at harvest, number of productive tillers, panicle length, amount of grain/panicle, amount of green grain/panicle, and dry gain production. Data were analysed using analysis of variance and Duncan Multiple Range Test for significant differences. The results of the study showed that the growth of rice cropping patterns A, B, and C were not different. However, rice production was significantly different, where pattern A, B, and C was 8.36 ± 1.48 t ha-1, 7.84 ± 1.24 t ha-1 and 7.48 ± 0.54 t ha-1 respectively.

Study of technology packages to support increasing production of chili pepper commodities in South Sulawesi

The purpose of the study is to obtain packages of chili pepper cultivation technology to support the increasing productivity of chili pepper in South Sulawesi. The study was held in Lengkese village, Mangarabombang District, Takalar Regency, South Sulawesi, Indonesia, from April to August 2019. The experimental design used Randomized Block Design, with three replications and five treatments: A = Maruti variety, closed nursery, black silver plastic mulch (BSPM), plant distancing 75 cm × 60 cm, a dosage of solid organic fertilizer 20 tons/ha, and 180 N, P, K kg/ha of inorganic fertilizers; B = Maruti variety, closed nursery, BSPM, plant distancing 75 cm × 60 cm, a dosage of solid organic fertilizer 10 tons/ha and 135 N, P, K kg/ha of inorganic fertilizers; C = Maruti variety, closed nursery, BSPM, plant distancing 75 cm × 40 cm, a dosage of solid organic fertilizer 10 tons/ha and 180 N, P, K kg/ha of inorganic fertilizers; D = Maruti variety, closed nursery, BSPM, plant distancing 75 cm × 40 cm, a dosage of solid organic fertilizer 20 tons/ha and 135 N, P, K kg/ha of inorganic fertilizers; and E= Maruti variety, open nursery, plant distancing 75 cm × 30 cm and dosage of inorganic fertilizers 127 N, 60 P, 60 K kg/ha. The results were showed that C treatment used the technology packages: Maruti variety, closed nursery, BSPM, plant distancing 75 cm × 40 cm, a dosage of solid organic fertilizer 10 tons/ha, and 180 N, P, K kg/ha of inorganic fertilizers produced more chili pepper weights per plant. The height of A and D treatment was significantly different from E treatment and resulted in the highest production of chili pepper, 14.97 tons/ha. Organisms such as Myzus persicae, fruit flies, Fusarium wilt disease, and anthracnose were found in low infestation rates. The technology packages can use to support the increasing production of chili pepper in South Sulawesi.

Organic waste processing and its application to potato plants through hydroponic techniques

The Kalimbu market is one of the traditional markets in South Sulawesi with a very high buying and selling activity. The organic waste that is mostly generated from the activities at the Kalimbu Market is leftover vegetables and fruit. Vegetable and fruit waste provides a big advantage if it is managed properly, which is converted into liquid organic fertilizer through a fermentation process. The liquid organic fertilizers produced can help farmers overcome the high price of synthetic fertilizers and save the earth from pollution. The method used to determine the effect of types of organic waste (vegetable waste and fruit waste) on the physical and chemical quality of solid and liquid organic fertilizers used a randomized block design. Whereas the application of solid and liquid organic fertilizers to the production and nutritional content of potato plants used a treatment consisting of P0: basic fertilizer + without liquid organic fertilizer and P1: basic fertilizer + liquid organic fertilizer. The results of research on the manufacture of liquid organic fertilizer from Kalimbu market waste with vegetable and fruit samples also showed that the two samples required different storage times for composting. Plants treated with liquid organic fertilizer from the Kalimbu market waste have better stem growth, leaf number, and stem number.Keywords: Waste, organic, fermentation, hydroponic

Peranan Pupuk Organik Kascing Untuk Mendukung Program KRPL Di KWT Melati Kelurahan Bandungrejosari Kecamatan Sukun Kota Malang

Pupuk organik berasal dari tumbuhan mati, kotoran hewan, dan limbah organik yang telah melalui proses rekayasa. Kascing (Bekas Cacing) merupakan salah satu pupuk organik padat yang berasal dari proses vermikompos yang dibantu oleh peranan cacing tanah (Lumbricus rubellus). Tujuan penelitian ini yaitu mengetahui kandungan pupuk organik kascing dengan melakukan uji laboratorium dan mengetahui dosis kascing dalam meningkatkan produksi pakcoy dengan melakukan rancangan percobaan. Penelitian dilakukan di lahan kampus Politeknik Pembangunan Pertanian Malang menggunakan Rancangan Acak Kelompok (RAK) dengan 6 perlakuan dosis kascing yaitu 0 g, 300 g, 400 g, 500 g, 600 g, 700 g, dan diulang sebanyak 4 kali. Analisa data diolah menggunakan Analysis of Varience (ANOVA) dengan taraf 5%, dan dilanjutkan dengan uji Duncan Multiple Range Test (DMRT) jika terdapat beda nyata dengan taraf 5%. Hasil uji laboratorium menunjukkan kandungan C-Organik : 35,43%, C/N Rasio : 23,16, N : 1,53%, P2O5 : 2,94%, dan K2O : 0,60%. Rancangan percobaan pengaruh pupuk organik kascing dengan dosis 0 g, 300 g, 400 g, 500 g, 600 g, dan 700 g terhadap pakcoy memberikan hasil berbeda pada parameter tinggi tanaman, jumlah daun, dan berat segar pakcoy. Sedangkan pada parameter panjang akar pakcoy memberikan hasil tidak berbeda.

Analysis and Characterization of Solid and Liquid Organic Fertilizer from Hydrothermal Carbonization (HTC) of Chicken Feather and Blood Waste

Conversion of feather and blood from chicken slaughterhouse waste for producing solid and liquid organic fertilizer excluding composting process with a variation of the mass ratio of feather and blood of a chicken has been conducted. The nitrogen, sulfur, and iron content in the solid and liquid product of the hydrothermal carbonization process were analyzed to identify and characterize the possibility of hydrolysate as a source of nitrogen, sulfur, and iron in soil fertilizer. Feather and blood of chicken waste were introduced to a hydrothermal carbonization reactor with the addition of limestone at a temperature range of 160–170 °C for the preparation of solid and liquid organic fertilizer. According to the FTIR interpretation, the solid product had functional groups such as NH, OH, CH sp3, SH, C=O, C=C, C–O–C, and C–H aromatic. The nitrogen, sulfur, and iron content of the optimal ratio in the solid phase were 4.67%, 1.63%, and 3694.56 ppm, while their contents in the liquid fertilizer were 3.76%, 1.80%, and 221.56 ppm, respectively. The vibration of 478 cm–1 is attributed to Fe–O paramagnetic (Fe2O3) confirmed by TEM images showed the diameter size less than 20 nm indicating the presence of superparamagnetic material.

Physical quality of some types of grass on mixed planting with Arachis pintoi and organic fertilizing

Increased livestock productivity is largely determined by the availability of sufficient forage. Good forage is determined by digestibility, which is related to physical quality. This study aims to determine the physical quality of several types of grass planted with Arachis legumes and the provision of organic fertilizer. This study used a Randomized Block Design with a factorial pattern consisting of 3 types of grass planted with Arachis legumes (factor A) and fertilizing 2 types of solid and liquid organic fertilizer (factor B) with 3 replications. The treatment combinations are: R1C (Paspalum notatum with Arachis pintoi+Compost), R1B (Paspalum notatum with Arachis pintoi+Biourine), R2C (Paspalum conyugatum with Arachis pintoi + Compost), R2B (Paspalum conyugatum with Arachis pintoi +Biourine), R3C (Axonopus compresus with Arachis pintoi+Compost), R3B (Axonopus compresus with Arachis pintoi+Biourine). The results showed no significant difference (P>0.05) both in the mixture of some grass plants with Arachis pintoi and the provision of organic fertilizer on the physical quality of forage. In planting a mixture of Axonopus comprsus grass with Arachis pintoi showed average dry matter (DM), water regain capacity (WRC), and water solubility (WS). Whereas compost gets higher average values than biourine for dry matter, WRC and WS. The combination of mixed planting and fertilizing, compost showed the highest average, especially water solubility (WS). From this research it can be concluded planting a mixture of grass and legumes fed with compost on average is better for the physical quality of the grass, but not significantly different (P>0.05) from all treatments.

Combination Effect of Solid Waste of Gracilaria Extraction and Sargassum Powder on Nitrogen Content of Bio Fertilizer

The solid waste of Gracilaria extraction contains agar, while Sargassum contains alginate. Both contain cellulose, hemicellulose, lignin, celite, micro and macronutrients, and plant growth promoters. In this research, the two ingredients were formulated to produce biofertilizers. The treatment given was a combination of solid waste of Gracilaria extraction (39, 48, 56, and 68%) with Sargassum flour (29, 20, 12, and 0%), while other organic matter became a fixed variable. The research aims to get the best combination of solid waste of Gracilaria extraction and Sargassum flour which produces the highest N content. The results showed that the best combination to produce the highest N content was LIA1 (39% solid waste of agar extraction and 29% Sargassum flour). However, LIA3 treatment (56% solid waste of agar extraction and 12% Sargassum flour) closed to the technical requirements of solid organic fertilizer. The characteristics of LIA3 fertilizer are 0.75% N content, 47.08% moisture content, 8.80 acidity degree, 6.85x109 cfu/g total bacteria and 41.95x104 cfu/g total mold.

Application of bokashi goat manure and organic liquid fertilizer to improve the growth and yield of Lembah Palu shallot variety

The study aims to determine the effect of the application of solid organic fertilizers from bokashi goat manure (BGM) and liquid organic fertilizer (LOF) of cow urine to improve the growth and yield of ’lembah palu’ shallot varieties. The study was conducted on farmers’ land in Sidera Village Subdistrict Sigibiromaru Sigi Regency in Central Sulawesi. Research using Random Complete Block Design (RCBD) in factorials design (two-factor) with three replications. The first factor is the application of BGM, consists of 2 levels, namely: (1) without BGM and (2) BGM 30 t ha-1; The second factor is the concentration of LOF consists of 3 levels: (1) without the LOF, (2) LOF 16 L ha-1 and (3) LOF 32 L ha-1. The results of the research showed that BGM 30 t.ha-1, followed by application of 16 L.ha-1 LOF produce shallot crop is higher, and the number of tuber per hill and the fresh weight of tuber per hectare of shallot ’lembah palu’ variety is higher compared with a combination of other treatments. BGM 30 t.ha-1 produced more leaf number and fresh weight of tubers per plant higher and significantly different without BGM. Application LOF 32 L.ha-1 produce of shallot leaves more than without LOF and LOF 16 L.ha-1.

STUDI KOMPARATIF PERTUMBUHAN RUMPUT MULATO PADA LAHAN PASCA TAMBANG YANG DIBERI PUPUK BERBEDA

To determine the effectiveness of the use of organic fertilizers on the growth rate of grass mulato (brachiaria hybrid cv mulato) which is planted on the soil after mining PT. Vale, bro. located in sorowako, East Luwu Regency, South Sulawesi Province. This Research was conducted using a completely randomized design (CRD) factorial (4 x 3) with 3 times replication for each treatment combination. Factor A as a type of fertilizer and Factor B as a cutting age. Experiments are 36 total units. The results showed that the plant height given liquid organic fertilizer was significantly higher (P <0.01) than the plant height rate in the post-mining soil which was given granular fertilizer. This difference occurs because liquid organic fertilizer is faster absorbed by plants than organic solid fertilizer (granules). Post-mining land which is used as a medium for mulato grass growth is actually not a barrier to use. The conclusion of this research is the use of organic fertilizers in the cultivation of grass mulato (Brachiaria hybrid cv. Mulato) on post-mining land gave a positive response. The use of organic liquid fertilizer provides the best response compared to the control and solid organic fertilizer (granule).

STUDI KOMPARATIF PERTUMBUHAN RUMPUT MULATO PADA LAHAN PASCA TAMBANG YANG DIBERI PUPUK BERBEDA

To determine the effectiveness of the use of organic fertilizers on the growth rate of grass mulato (brachiaria hybrid cv mulato) which is planted on the soil after mining PT. Vale, bro. located in sorowako, East Luwu Regency, South Sulawesi Province. This Research was conducted using a completely randomized design (CRD) factorial (4 x 3) with 3 times replication for each treatment combination. Factor A as a type of fertilizer and Factor B as a cutting age. Experiments are 36 total units. The results showed that the plant height given liquid organic fertilizer was significantly higher (P <0.01) than the plant height rate in the post-mining soil which was given granular fertilizer. This difference occurs because liquid organic fertilizer is faster absorbed by plants than organic solid fertilizer (granules). Post-mining land which is used as a medium for mulato grass growth is actually not a barrier to use. The conclusion of this research is the use of organic fertilizers in the cultivation of grass mulato (Brachiaria hybrid cv. Mulato) on post-mining land gave a positive response. The use of organic liquid fertilizer provides the best response compared to the control and solid organic fertilizer (granule).

Crop performance and soil fertility improvement using organic fertilizer produced from valorization of Carica papaya fruit peel

In recent times, research attention is focusing on harnessing agricultural wastes for the production of value-added products. In this study, the valorization of Carica papaya (Pawpaw) fruit peels was evaluated for the production of quality organic fertilizer via anaerobic digestion (AD) while the effects of the fertilizer on maize crop were also assessed. Pawpaw peel was first pretreated by thermo-alkaline methods before AD and analyses were carried out using standard methods. The resulting digestate was rich in nutrients and was dewatered to form solid organic fertilizer rich in microbes and soil nutrients. When applied to maize plants, organic fertilizer showed a better effect on plant traits than NPK 15–15–15 fertilizer and without fertilizer application. These were more pronounced at mid to high organic fertilizer applications (30-to-60-kg nitrogen/hectare (kg N/ha)) rate. Comparison between the values obtained from the field experiments reveals that the organic fertilizer showed better performance in all parameters such as the number of leaves, leaf area, plant height, stem girth, total shoot, and root biomass, and length of the root. However, the chemical fertilizer outperformed all the organic fertilizer applied rates in the average highest size of the corn ear by 1.4%. After harvesting, nutrient elements were found to have bioaccumulated in plant organs (leaves, stem, and root) with the highest values being 29.7 mg/L for nitrogen in the leaf and this value was reported from the experiment with 50 kg N/ha. For phosphorus and potassium, the highest concentrations of 7.05 and 8.4 mg/L were recorded in the plant’ stem of the experiment with 50 kg N/ha. All the treated soils recorded an increase in values of all nutrient elements over the control with the highest values recorded in the experiment with 60 kg N/ha. In soil with 60 kg N/ha, the nitrogen, phosphorus, and potassium increased by 28, 40, and 22% respectively over the chemical fertilizer applied experiment while different levels of increases were also recorded for all other macro and microelements in all the experiments. Thus, agricultural practices by using anaerobic digestates as organic fertilizers is a sustainable method to overcome the dependence on inorganic fertilizers high rate.

Utilization of organic fertilizer in response to mitigate CO2 emission

Food security and sovereignty are strategic policy agenda of national security. Accelerating the growth of sustainable food production and improving the welfare of farmers through optimization of land resources are the priority. One way to increase food production and enhance soil quality is through the utilization of organic fertilizers such as livestock waste. In addition, it is expected to reduce CO2 emissions rather than leaving manure untreated. The purpose of this study was to determine the effect of solid manure and biourine application on increasing maize production and mitigate CO2 emission. This study was conducted in Inceptisols Rasau Jaya II, West Kalimantan. A randomized complete block design trial was established from plots fertilized with solid organic fertilizer (PO), biourine (BIO), solid organic fertilizer+biourine (PO+BIO), and control, with five replications. Parameters observed in this study were CO2 flux and agronomic performance of maize. CO2 emission was measured using the static chamber method, placing chambers on the surface of the soil and taking measurements using an infrared gas analyzer for 125 days. CO2 fluxes ranged from 59.93 to 106.07 Mg ha-1 yr-1 and there was no significant difference among the organic fertilizer treatments; nevertheless, the lowest CO2 flux was illustrated in PO+BIO. Maize productivity was influenced by the organic fertilizer and PO+BIO had the greatest maize yield.

Combined Acidification and Solar Drying of Pig Slurries for Nutrient Recovery and Controlled Atmospheric Emissions

The solar drying of pig slurries was tested in a pilot-scale greenhouse (10 m2 footprint), operated with forced ventilation under low and high solar irradiation in Mediterranean conditions. Gaseous emissions were prevented through slurry acidification and by the biofiltration of exhaust gases. Air relative humidity and temperature in and out the greenhouse, as well as the weight of a slurry sample, were monitored online to command the ventilation regime. Daily average drying rate values ranged from 0.3 to 2.8 kg m−2 d−1 and displayed a direct dependency with solar radiation until the pig slurry lost a 60% of its initial weight, with a solar energy efficiency of about 26%. Upon further drying, the water content from pig slurries stabilized at around 10%. Mass balances between the initial slurry and dried product were closed for total solids and organic matter, but the recovery of nutrients ranged from 69% to 81%, apparently because of precipitation and incrustation phenomena. The NPK composition of the final product was 4.3–2.5–3.8 and fulfilled current regulations for solid organic fertilizers. Operational costs of the drying process and fertilizing quality parameters were also discussed.