Cultivation of ruziziensis grass (Urochloa ruziziensis) using swine liquid manure fertilization

The objective of this study was to evaluate the use of liquid swine manure (LSM) as fertilization in the implantation of Urochloa ruziziensis. The experimental design was randomized blocks with five treatments and four replications, with the treatments being four doses of LSM (0; 100; 200 and 300 m3 ha-1) and one dose of mineral fertilization. Seven cuts were carried out uniformly, after which plant height (PH), total dry mass yield (TDMY), crude protein content (CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF), macromineral extraction (N, P, K, Ca, Mg and S) and microminerals (Fe, Zn, Mn and Cu) of plants were evaluated every 30 days. Mineral fertilization provided higher PH, CP content and extraction of N and S, but lower NDF content. For ADF variable, there was no difference between treatments. The results of dry mass yield (DMY) and extractions of P, K, Ca and Mn showed that the effect of 300 m3 ha-1 LSM was statistically equal to mineral fertilization. For extractions of Mg, Fe, Zn and Cu doses of 200 and 300 m3 ha-1 did not differ statistically from mineral fertilization. Among the doses of LSM, there was increasing linear effect, with increases in the variables DMY (30.89%), PH (14.94%), CP (17%), N (53.01%), P (40.79%), K (27.84%), Ca (35.17%), Mg (29.6%), S (47.13%), Fe (31.2%), Zn (31.6%) and Mn (23.04%). For Cu extraction, there was a quadratic effect with the highest extraction in the dose of 26.36 m3, obtaining an increase of 19.94% in relation to treatment without application. It is important to study different LSM dosages to avoid risk of heavy metal toxicity. The LSM is an alternative in place of mineral fertilization for Urochloa ruziziensis grass.

Isotherms, Kinetics, and Thermodynamics of NH4+ Adsorption in Raw Liquid Manure by Using Natural Chabazite Zeolite-Rich Tuff

The search for safer and sustainable management of animal manure is a global and topical challenge, in particular for the reduction of nitrogen (N) content. The use of natural adsorbents as zeolite-rich tuffs is recognized as a valid method to recover N, in the form of ammonium (NH4+), from animal manure. While the scientific literature is rich in studies performed on synthetic solutions and using clinoptilolite zeolites as adsorbent, it lacks information concerning adsorption in real liquid manure and using other types of zeolite-rich tuffs (e.g., chabazite). This work aims at exploring the NH4+ adsorption process from raw liquid swine manure, using a chabazite-rich zeolite tuff as adsorbent. The effects of temperature, contact time, and grain size have been assessed. Isotherms, kinetic models, and thermodynamic parameters have been investigated. Harkins-Jura isotherm correlates well with the observed data, in accordance with the formation of an adsorption multilayer. Kinetic data have been explained by intraparticle diffusion and pseudo-second-order models. In conclusion, the natural chabazite tuff has proven to be a valid material for NH4+ adsorption from raw liquid swine manure. In particular, to reach the highest adsorption capacities and adsorption rates, it is recommended to use it at a fine particle size and with dosages < 6 %.

Reduction of Nitrogen Load in a Zootechnical Wastewater Using a Natural Chabazite Zeolite: An Investigation on Sorption Mechanisms

The use of zeolite-rich tuffs is a valid method for recovering nitrogen from wastewaters. This paper aims at describing the NH4+ adsorption processes of an Italian chabazite zeolite tuff used for the treatment of raw liquid swine manure. The effects of temperature, grain size and contact time were investigated. The isothermal analysis showed a multilayer adsorption behavior, well explained by the Harkins–Jura model, while kinetics was explained by pseudo-second-order, Elovich and intraparticle diffusion models. This study highlighted the complexity of the adsorption process from raw liquid manure, as well as the significant differences between tested particle sizes of the same zeolite tuff.

Responses of Soil Microbial Activity to Swine Manure Applications

The allocation of the large amount of swine waste from farms is an international concern. An efficient way of managing such waste is its use in farming. It is already known that the incorporation of organic waste into the soil significantly increases the microbial population. Therefore, the objective was to evaluate the impact of the use of swine manure on the soil microbiota in a Eutrophic Oxisol. The experiment was set up in a completely randomized design in a 6 &times; 4 factorial scheme (sixconcentrations of swine manure and four evaluation periods) with four replications. We evaluate the following characteristics: microbial respiration (C-CO2), microbial biomass (&micro;C g-1 soil) and pH.: microbial respiration (C-CO2), microbial biomass (&micro;C g-1 soil) and pH. A significant effect was found in the interaction between concentrations and time of incubation (p &lt; 0.05) of swine manure on microbial activity in the soil. The amount of microbial carbon increased as a function of increased levels of liquid swine manure. No interaction was observed between concentrations and time of incubation for the pH. The evaluation of the isolated factors allowed to observe that the pH decreased as the doses of manure were incremented. Higher and lower pH values were found after 5 and 30 days of incubation. The application of liquid swine manure up to 6000 L ha-1 increases the release of CO2 and carbon in the microbial biomass. The applications of liquid swine manure cause a gradual reduction in soil pH.

Phosphorus Contents in the Profile of an Oxisol With Continuous Application of Liquid Swine Manure

This study aimed to evaluate the dynamics of phosphorus in the soil by the determination of phosphorus contents in an Oxisol cultivated with soybean during the 2016/2017 crop season, after 17 years of successive applications of liquid swine manure (LSM). The experiment was conducted in the experimental area of the University of Rio Verde. The treatments were: T1-control; T2-25 m3 ha-1 of LSM; T3-50 m3 ha-1 of LSM; T4-75 m3 ha-1 of LSM; T5-100 m3 ha-1 of LSM and T6-fertilization with mineral fertilizer. The subplots refer to soil depths: 0-10; 10-20 and 20-40 cm. The LSM was applied to the soil surface by spraying, before soybean sowing and the mineral fertilizer was applied to the furrow at the time of planting. After soybean harvesting, soil samples were collected at the studied depths for the determination of the contents of P in the soil. The contents of P in percolated water are within the concentration range considered adequate for human consumption. As for the contents of P in the soil, LSM applications on the soil surface increased the available soil P up to the depth of 20 cm. The highest dose of LSM applied to the soil promoted an increment of P contents that are within the safety range of the critical environmental limit of phosphorus (LCA-P), corresponding to 37% of this limit.