Greenhouse Assays with Lactuca sativa for Testing Sewage Sludge-Based Soil Amendments

Sustainable agriculture practices within the guidelines of nutrient recycling and the circular economy must be increasingly promoted. This work aims to evaluate the performance of dried sewage sludge (DSS), green liquor dregs mixed with sewage sludge (DSSA), raw sewage sludge, and commercial organic fertilizer control, using a short-term agronomic assessment with lettuce crop (Lactuca sativa) in greenhouse conditions. Different application rates based on the nitrogen content were tested for each soil amendment: 0, 85, 170, and 225 kg N/ha (treatments T0, T1, T2, and T3, respectively). DSS and DSSA resulted in fresh lettuce productivities 1.3 and 3.2 times higher in T3 than in T0, respectively. The ideal N content in lettuce leaves was reached for all materials and treatments, with the highest values obtained for DSS (2.88–3.33% from T1 to T3). Lettuce produced in soils amended with DSS and DSSA showed also ideal levels of Ca. Overall, the performance of sludge-based products was similar to commercial fertilizer, without impairing the nutritional balance of the crop and the soil.

Phytoremediation of a Polluted Soil by Purple Plant (Tradescantia pallida L.) Under Different Organic Amendments

Present investigation was performed to determine the ability of purple plant (Tradescantia pallida L.) for removing heavy metals from a contaminated soil particularly nickel, with the aid of different types of organic amendments. Results of soil heavy metal content after application of different fertilizers were: maximum values (ppm) of V, Cr, Ni, Mn, Cu, Zn, As, Mo, Cd, Pb and Ag were respectively: 275.437, 284.807 (control 1), 265.073, 1071.32, 60.0671 (control 2), 77.8288, 9.5162, 8.5267 (control 1), 5.7943 (control 1), 7.5076 (control 2) and 37.8868 (control 1). Whereas, the minimum values (ppm) of V: 104.644, Cr: 85.7222 (commercial fertilizer), Ni: 164.92, Mn: 711.155 (cow dung), Cu: 15.5141 (cow dung), Zn: 43.3929 (commercial fertilizer), As: 3.7819 (cow dung), Mo: 0.000 (plant residue composite and bird manure), Cd: 0.000 (plant residue composite and bird manure), Pb: 4.1535 (bird manure) and Ag: 2.9181 (plant residue composite). This indicate that the use of organic amendment induce the phytoremediation of polluted soils.

EVALUATION OF DRIPPER EFFICIENCY WITH THE USE OF FERTILIZER

The objective of the work was to analyze the uniformity of drip fertigation compared to the use of water alone, analyzing by the Tukey test at 5% significance for CUC and DUC, defining the process capability from the process capacity index (Pc) . The experiment was carried out on a test bench in the irrigation and fertigation laboratory (LIF) of the University of Western Paraná, where in the first treatment, water was used for the irrigation process and in the second treatment, commercial fertilizer was diluted in the reservoir to perform the fertigation. The experimental statistics is constituted in an analysis of variance with subsequent unfolding of the interaction and Tukey test at 5% probability to compare the averages of uniformities, flow and pressure of the system. Finally, the process capability (Pc) was defined for the distribution uniformity variable. The results showed statistical superiority for the fertigation process, however, it is noteworthy, that both treatments achieved excellence in their classifications with values ​​above 90% for both CUC and DUC, according to the reference.

Unveiling the Solubilization of Potassium Mineral Rocks in Organic Acids for Application as K-fertilizer

Organic acids produced by soil microorganisms can be useful to promote the release of potassium (K) from potassium mineral rocks (KR), but the complexity of low-reactivity minerals limits K solubilization and their use as fertilizer. Here, we investigate the ways that different organic acids (gluconic, oxalic, and citric) can affect the solubilization of potassium minerals, in order to propose process strategies to improve their solubility. For this, evaluations were performed using the model minerals KRpolyhalite (sedimentary mineral), KRfeldspar (igneous mineral), and KCl (commercial fertilizer). For KCl and KRpolyhalite, complete solubilization was achieved using all the organic acids, while for KRfeldspar, the highest K+ solubilization (34.86 mg L-1) was achieved with oxalic acid. The solubility of KRfeldspar was further investigated under submerged cultivation with the filamentous fungus Aspergillus niger, as well as after a mechanochemical grinding treatment. The biotechnological route resulted in solubilized K+ up to 63.2 mg L-1. The mechanochemical route, on the other hand, increased the release of K+ by about 8.6 times (993 mg L-1) compared to the natural mineral, due to the greater fragmentation of the particles after the treatment (with a surface area about 2.5 times higher than for the in natura KRfeldspar). These findings demonstrated the potential of applying biotechnological and mechanochemical routes with organic acids to improve the solubilization of K present in low reactivity mineral rocks, contributing to the use of these minerals as fertilizers in more sustainable agricultural practices.

Towards a Full Circular Economy in Biogas Plants: Sustainable Management of Digestate for Growing Biomass Feedstocks and Use as Biofertilizer

The digestate is a prospective biofertilizer and potential source of income for many biogas plants worldwide. However, its actual impact on the soil properties and biomass yield is still unexploited. The different digestates from eight agricultural biogas plants were researched in terms of their chemical composition and the fertilizing potential. The results obtained from digestate chemical analysis indicate that the digestate biomass had large amount of nitrogen (up to 73 g kg−1 fresh mass) and potassium (up to 25 g kg−1 fresh mass). The value of the digestate was estimated in the range of 2.88–7.89 EUR Mg−1 for liquid digestate and 7.62–13.61 EUR Mg−1 for solid digestate based on the commercial fertilizer market price of nitrogen, potassium phosphorus, organic carbon, Cu, Zn, Fe and Mg. The digestate produced at the 1 MW biogas plant is worth EUR 941–2095 per day in addition to energy sales income. The application of digestate on low-fertility land in areas close to the biogas plant allows the production of up to three-fold more biomass suitable for biogas production. The digestate’s application on semi-natural grass biomass production in the low-fertility soils near the biogas plants could be an alternative strategy for the biogas plant feedstock portfolio diversification.

Bokashi, simple superphosphate, and fertigation for the growth and nutrition of hybrid Cattleya (Orchidaceae)

Potted flower production is an important floricultural activity. However, there have been few studies on the fertilization management of orchids. Fertigation with urea and potassium chloride is feasible, but little information is available regarding the interaction of these fertilizers with other sources of nutrients. Thus, the present study evaluated the effects of application of bokashi and a simple superphosphate and their interactions with fertigation on the growth and nutrition of hybrid Cattleya. Seedlings of Laeliocattleya Drumbeat × Laeliocattleya Gold Digger hybrid were submitted to two ferti-irrigation levels (absent and present) using urea and potassium chloride as nitrogen and potassium sources, respectively. As complementary fertilization, bokashi and superphosphate were applied singly and in combination. A commercial fertilizer (Peters®) was used as an additional control. Fertigation increased plant height; leaf area; number, length, and diameter of pseudobulbs; dry mass of leaves, pseudobulbs, and roots; and content of chlorophyll, carotenoid, and nitrogen. The application of bokashi resulted in dry mass gain in all plant organs. The combination of fertigation and bokashi was superior to the commercial fertilizer in terms of increased leaf area, chlorophyll A content, carotenoid content, and dry mass.

RESEARCH ON THE HYDROLYSIS PROCESS OF SOYBEAN POWDER BY ALCALASE TO PRODUCE COMMERCIAL FERTILIZER

Mục đích của nghiên cứu là khảo sát đơn yếu tố tỉ lệ phối trộn thích hợp giữa enzyme (E) và chế phẩm vi sinh vật có ích (EM), tỉ lệ nước bổ sung, nhiệt độ ủ, thời gian thủy phân ảnh hưởng tới quá trình thủy phân khô đậu tương bằng chế phẩm enzyme alcalase. Hàm lượng protein hòa tan trong dịch thủy phân được xác định bằng phương pháp Lowry. Kết quả khảo sát tương ứng là: EM 2% + E 1.5%; 4 (ml/g); 45ºC; 8 h. Trên cơ sở khảo sát các yếu tố ảnh hưởng đến điều kiện thủy phân, chúng tôi nhận thấy tỷ lệ phối trộn giữa enzyme và EM, tỷ lệ nước bổ sung, nhiệt độ ủ, thời gian thủy phân là những yếu tố ảnh hưởng mạnh đến quá trình thủy phân. Bằng phương pháp quy hoạch thực nghiệm Box- Behnken đã tìm được điều kiện tối ưu quá trình thủy phân khô đậu tương là tỷ lệ phối trộn giữa enzyme và EM là EM 2% + E 1.5%, tỉ lệ nước bổ sung là: khô đậu tương: 4.2, nhiệt độ ủ 45ºC, thời gian thủy phân 8.53 giờ. Kết quả thực nghiệm cho kết quả có độ tương thích cao với mô hình.

Isolation of Sludge Protein from Skin Fleshing Wastes by Alkaline Hydrolysis and Determining its Effects as a Fertilizer on Growth of Some Nursery Plants: A Step Towards Tanneries Waste Utilization in Pakistan.

During Leather Processing, Skin Fleshing Wastes (SFW) are usually disposed of in an open area which creates toxic hazards. In this study, (SFW) from tanneries have been hydrolyzed using two alkalis Potassium hydroxide ( 2g/ 100g of SFW ) and Sodium hydroxide ( 4g/100g of SFW) with a sufficient amount of water at 2300 F in Autoclave for two hours. Three resultant fractions fats and oil (approximately 240 g Kg-1 ), protein (approximately 554 g Kg-1 ) and sludge containing a high amount of ashes (approximately 900 g Kg-1 ) were successfully isolated respectively. The yield of fractions was calculated on the wet weight of SFW used after the removal of lime using ammonium sulphate. In this study, the isolated third fraction Fleshing Sludge (FS) from the hydrolyzed fleshing wastes used fertilizer on the six different plants on growth commonly named Ghobi, Cran Dola, Patunia, Placus, Dentist and Dalia. The observations were taken during 30 days of incubation, at the usual temperature. The application of FS in plants observed that growth was enhanced in significant proportion as compare to reference plants supplemented with commercial fertilizer except in the Ghobi sample PS1 which shows some phytotoxicity confirmed by leaf yellowing. The results revealed that the applied sludge has no adverse effect on the growth of other experimental plants. Results were taken by measuring plants according to standard methods

Inputs: Potassium Sources for Agricultural Systems

In the potassium (K) cycle, inputs encompass all K sources that move into a given volume of soil. These inputs may include atmospheric deposition, irrigation water, runoff, erosion, as well as seeds, cuttings, and transplants. Accounting for all inputs is seldom routinely done on the farm. Many K inputs have variable concentrations, making estimations difficult. Estimates for added K are provided in some planning documents and can be used where testing of on-farm inputs is not feasible, although testing is preferred. Standard commercial fertilizers have known concentrations of K and are concentrated enough to be economical to transport long distances. The global reserves for their production have an estimated lifetime of thousands of years. This chapter emphasizes considerations for using various commercial fertilizer sources.