Integral Assessment of Organic Fertilization on a Camelina sativa Rotation under Mediterranean Conditions

The goal of this study was to provide quantitative agronomic data and environmental performance through a life cycle assessment of camelina in a crop rotation. For this purpose, camelina [Camelina sativa (L.) Crantz] was included in a crop rotation (camelina-barley [Hordeum vulgare (L.)]-camelina) fertilized with two organic fertilizers (dewatered sludge and composted sludge) during three growing seasons (2015–2018). Three treatments were considered in this experimental study of 0.018 ha: (1) Fertilization with composted sludge (15 t ha−1), (2) fertilization with dewatered sludge (35 t ha−1), and (3) control treatment without fertilization. Results showed that camelina’s yield was affected by climatic conditions, ranging from 0.9 to 1.4 t ha−1 in the first season (2015/2016) and the third season (2017/2018 and did not present significant differences between treatments. The yield components with a positive response to organic fertilization were number of silicles, number of seeds per plant, and thousand-seed weight, with an average increase compared to the control of 23.7%, 16.5%, and 18.5%, respectively. A negative correlation was observed between organic fertilization and total fat content, contrary to the increase in protein content observed with organic fertilization. The environmental assessment of this crop rotation revealed that fertilization and transport were the main hotspots. Despite the undesirable weather limitations, this study showed a positive response of camelina’s yield components and seed quality to organic fertilization. By applying these organic fertilizers, it may be possible to obtain favorable camelina yields and promote waste valorization. To minimize the environmental impacts of this crop rotation with camelina, the main recommendations could be to reduce the distances between the dewatering and composting sites and the field and optimize fertilization rates. Further research is needed to determine the application of these organic fertilizers in the long term.

ASSESSMENT OF SEAFOOD PROCESSING SLUDGE AFTER COMPOSTING ON GROWTH OF TAGETES PATULA L.

Sludge of seafood processing factories discharged directly into the environment can lead to environmental pollution. Research on the use of seafood processing sludge as compost for agriculture in the Mekong Delta is encouraged. The objectives of this study were (1) to evaluate the chemical composition of seafood processingsludge after 60 days composting and (2) to evaluate the growth of Tagetes patula L planted with composted sludge. The sludge composting experiment was carried out with 3 treatments: sludge + Trichoderma fungi; sludge + chicken manure + Trichoderma fungi; sludge + straw + chicken manure + Trichoderma fungi. The results showed that the treatment of sludge + straw + chicken manure + Trichoderma fungi had a betterquality than the other two treatments. The pH, TC, TN, NH+ 4 , NO- 3 , TP, PO3 4- and heavy metal(Pb, Cd, Cr, Cu, Ni, Zn and Hg) contents of sludge meet the environmental standard of Viet Nam (10TCN526:2002). E. coli and Salmonella were not present at the end of the composting experiment. Tagetes patula L grew and flowered on all 4 treatments: control – composted straw; sludge + Trichoderma fungi; sludge + chicken manure + Trichoderma fungi; sludge + straw + chicken manure + Trichoderma fungi. However,Tagetes patula L grew best on the sludge + Trichoderma fungi experimental condition .

Evaluation of Yield and Quality Attributes of Grafted Brinjal under Treated Paperboard Mill Effluent Irrigation and Sludge Application

Field experiment was conducted to assess the impact of paperboard mill sludge compost and treated paperboard mill effluent irrigation on growth and yield of grafted brinjal. Among the different treatment combinations, application of phosphorus enriched ETP sludge compost at 5 t ha-1 along with treated effluent through drip irrigation and recommended level of NPK (200:150:100 kg NPK ha-1) resulted the highest brinjal yield of 42.7 t ha-1. There were no adverse effects on soil properties due to sludge compost application and treated effluent irrigation. Quality attributes of the fruits which include anthocyanin content, total phenol content, ascorbic acid content, titrable acidity and protein content were not affected due to the composted sludge application along with treated effluent irrigation. Thus, the treated effluent and the composted sludge which complies with the state pollution control board norms can be used as a viable alternative source of irrigation and nutrients for grafted brinjal cultivation without adversely affecting on crop quality.

Uso de lodo de esgoto na produção de mudas clonais de Eucalyptus

Sewage sludge is a by-product of wastewater treatment facilities and in most cases, it is not properly managed being deposited in landfills. This waste has all essential nutrients for the mineral nutrition of plants in addition to having high levels of organic matter which promotes greater water retention, improving the physical and biological soil attributes. The aim of the current research was to evaluate substrates of composted sewage sludge and commercial substrate with different mixtures in H13 clone seedlings (Eucalyptus grandis x Eucalyptus urophylla) by evaluating biotic factors (plant height and diameter), dry matter production, seedling quality, mineral nutrition of plants, and chemical characteristics of the substrate. The experimental design was completely randomized with 5 treatments and 4 repetitions composed of 352 seedlings per plot. The treatments were: T1 - 100% composted sludge; T2 - 75% composted sludge and 25% commercial substrate; T3 - 50% composted sludge and 50% commercial substrate; T4 - 25% composted sludge and 75% commercial substrate; T5 - 100% commercial substrate. Plants with a greater amount of sewage sludge in the substrate performed better in all evaluated parameters.

Long Term Impact of Sludge Application in Maize Farm

Intensification of agriculture worldwide has led to a growing awareness on their environmental impacts, namely on soil quality and long term impact on crop productivity. As a consequence, there is an increasing concern regarding best agricultural management practices and their impact on physical, chemical and biological soil properties. In the Centre region of Portugal, maize is one of the most important arable crops and represents more than 32% of the cultivated area. Maize fields have been intensively managed under conventional practices, but increasing land degradation is leading farmers to adopt improved management practices, such as the application of composted sludge from urban wastewater treatment plants. This study aims to assess the long term impact of composted sludge application as soil amendment in maize cropping fields. The study was performed in Baixo Mondego, in central region of Portugal, largely devoted to agriculture and where maize is one of the most relevant crops. The study was performed in two study sites with similar soil and weather characteristics - one managed under conventional practices, with intensive application of fertilizers, and another field where a significant part of mineral fertilizers is replaced by composted sludge. Both sites use these agricultural management practices for more than 5 years. In 2018, two soil sampling campaigns were performed to assess the physical (texture and bulk density) and chemical soil properties (organic matter content, total nitrogen, total and extractable phosphorus, exchangeable cation (K+, Ca2+, Na+, Mg2+) and heavy metals (Cd, Cr, Pb, Zn and Ni)). Results show that composted sludge improves soil organic matter content (1.2% vs. 2.2%), total (2747 mg kg-1 vs. 1134 mg kg-1) and available phosphorous (821.85 mg kg-1 vs. 98.44 mg kg-1) comparing with conventional management practices. Higher contents of heavy metals, specifically Cu, Zn, Cd and Cr, were found in the field with sludge application than in the conventional one, which may represent a long term risk for soil contamination. Information regarding the long term impacts of best management practices on soil quality is relevant and should guide farmers and policy makers to attain agricultural sustainability.

Content of Heavy Metals in Soil and in Pineapple Fertilized With Sewage Sludge

The usage of sewage sludge in agriculture can increase the levels of heavy metals in the soil, compromising their use as fertilizer. The objective of this study was to evaluate the contamination of soil and pineapple by heavy metals after the application of treated sewage sludge by different forms in three orders of soils under greenhouse conditions. The treatments, in a factorial scheme 7 × 3 were distributed in a randomized complete block design with three replications, corresponding to seven fertilization management: soil without fertilization, chemical fertilization, fertilization with composted sludge sewage, fertilization with vermicompost sewage sludge, fertilization with solarized sewage sludge, fertilization as sewage sludge dried in a Bruthus-Albrecht rotary sludge dryer and fertilization with limed sludge sewage, combined with three orders of soils: Cambisol, Nitisol and Acrisol. The Zn, Cu, Cr, Pb, Ba, Cd, Ni, As and Se contents were analyzed in the soil, in the leaf of greater length (D leaf) and in the fruit pulp of the pineapple. The Acrisol provided more favorable conditions to the increase in the availability and absorption of Pb and As by D leaf and fruit of the pineapple. Fertilization with composted, vermicompost and solarized sewage sludge provided high levels of Pb, As, Zn in leaf D and in the pineapple fruit, relating the interference of sludge stabilization process with the absorption of metals by pineapple fruits.