C.M.d.S. Cordovil

Effects of solid phase from pig slurry on iron, copper, zinc, and manganese content of soil and wheat plants

Abstract A two‐year lysimeter experiment was conducted using winter wheat plants on two texturally contrasting soils (soil A and soil B). The main objective of this study was to evaluate the influence of increasing doses (5, 10, 15, 20, and 251 ha‐1) of solid phase from pig slurry (SP) on soil extractable copper (Cu), zinc (Zn), iron (Fe), and manganese (Mn) and on wheat micronutrients composition and uptake. As the control, a basic dressing of NPK fertilizer was applied. Results showed that increasing additions of SP significantly enhanced extractable Cu, Zn, Fe, and Mn content on the topsoil for both soils tested. In addition, a significant increase was detected for extractable Cu, Zn, and Mn content with increasing application rates of SP for subsoil A, but no significant differences were detected for subsoil B. A significant increase in the contents of Fe, Mn, and Zn in the plants as well as total uptakes were observed from increasing doses of SP. Copper content in the plants was not significantly aff...

Effects of solid phase from pig slurry on soil chemical characteristics, nitrate leaching, composition, and yield of wheat

Abstract A two years lysimeter experiment was carried out using wheat plants (Triticum aestivum L. cv. Lotti) on two texturally contrasting soils. The main purpose of this study was to evaluate the influence of increasing applications (5,10, 15,20, and 25 t.ha‐1) of solid phase (SP) from pig slurry on soil nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and sodium (Na) content, nitrate‐N (NO3‐N) leaching as well as on wheat composition and yield. As the control, a basic dressing of NPK fertilizer was applied. Results showed that plant growth was stimulated by increasing amounts of SP, yet the additions of 15 to 20 t SP ha‐1 led to similar effects on yield as that for the control. An accumulation of P on both soils was observed as well as a significant increase on NO3‐N leaching due to increasing rates of SP added to the soils. The N and P content in wheat plants (straw and grain) increased with increasing rates of applied SP.

Comparison of Chemical Methods of Assessing Potentially Available Organic Nitrogen from Organic Residues Applied to a Sandy Soil

Abstract More than 90% of the nitrogen (N) in soils is bond as organic N compounds. The available N can be estimated on the mineral N released during time‐consuming incubations of soil. Several chemical methods have been developed as substitutes for incubations. On the other hand, there has been an increase in waste production. Residues could potentially offset the need for mineral fertilizers, being both an economic and environmental benefit. Thus, the development of a routine method for prediction of N supply both from soil organic matter (SOM) and the application of organic residues is of great interest. An incubation experiment was performed in a Cambic Arenosol to evaluate different chemical methods. Air‐dried soil was mixed with increasing amounts of composted solid municipal waste, secondary pulp‐mill sludge, hornmeal, poultry manure, the solid phase from pig slurry, and composted pig manure. Samples were incubated for 244 days under a controlled environment. Among the chemical extractants studied, hot 2 M potassium chloride (KCl) and hot 0.01 M calcium chloride (CaCl2) showed promise in indicating values of N0 (potentially available nitrogen), and these simple methods are suitable for use in routine laboratory conditions.

Nitrogen-neutrality: a step towards sustainability

We propose a novel indicator measuring one dimension of the sustainability of an entity in modern societies: Nitrogen-neutrality. N-neutrality strives to offset Nr releases an entity exerts on the environment from the release of reactive nitrogen (Nr) to the environment by reducing it and by offsetting the Nr releases elsewhere. N-neutrality also aims to increase awareness about the consequences of unintentional releases of nitrogen to the environment. N-neutrality is composed of two quantified elements: Nr released by an entity (e.g. on the basis of the N footprint) and Nr reduction from management and offset projects (N offset). It includes management strategies to reduce nitrogen losses before they occur (e.g., through energy conservation). Each of those elements faces specific challenges with regard to data availability and conceptual development. Impacts of Nr releases to the environment are manifold, and the impact profile of one unit of Nr release depends strongly on the compound released and the local susceptibility to Nr. As such, Nneutrality is more difficult to conceptualize and calculate than C-neutrality. We developed a workable conceptual framework for N-neutrality which was adapted for the 6th International Nitrogen Conference (N2013, Kampala, November 2013). Total N footprint of the surveyed meals at N2013 was 66kgN. A total of US

Biochars in soils: towards the required level of scientific understanding

3050 was collected from the participants and used to offset the conference’s N footprint by supporting the UN Millennium Village cluster Ruhiira in SouthWestern Uganda. The concept needs further development in particular to better incorporate the spatio-temporal variability of impacts and to standardize the methods to quantify the required N offset to neutralize the Nr releases impact. Criteria for compensation projects need to be sharply defined to allow the development of a market for N offset certificates. S Online supplementary data available from stacks.iop.org/ERL/9/115001/mmedia

Wheat yield and leachability of phosphorus and mineral nitrogen in pig slurry amended Soils

Key priorities in biochar research for future guidance of sustainable policy development have been identified by expert assessment within the COST Action TD1107. The current level of scientific understanding (LOSU) regarding the consequences of biochar application to soil were explored. Five broad thematic areas of biochar research were addressed: soil biodiversity and ecotoxicology, soil organic matter and greenhouse gas (GHG) emissions, soil physical properties, nutrient cycles and crop production, and soil remediation. The highest future research priorities regarding biochar’s effects in soils were: functional redundancy within soil microbial communities, bioavailability of biochar’s contaminants to soil biota, soil organic matter stability, GHG emissions, soil formation, soil hydrology, nutrient cycling due to microbial priming as well as altered rhizosphere ecology, and soil pH buffering capacity. Methodological and other constraints to achieve the required LOSU are discussed and options for efficient progress of biochar research and sustainable application to soil are presented.

Espresso coffee residues as a nitrogen amendment for small‐scale vegetable production

Abstract An outdoor pot experiment was conducted using wheat plants (Triticum aestivum L. cv. Lotti). Each pot was filled with the upper layer of either a Cambic arenosol (soil A) or a Dystric cambisol (soil B) removed from the correspondent lysimeter where a two‐year wheat experiment (1993–1995) had been carried out with an equivalent experimental design as in the present study. The main objectives of this research were (1) to study the effects of increasing applications (5, 15, and 25 t ha‐1) of solid phase from pig slurry (SP) on wheat yield and tissue elemental composition and (2) to investigate the risk of contamination of drainage water by leaching of phosphorus (P) and mineral nitrogen (Nmin) as a result of those applications to the soil. The control consisted of a basic dressing of NPK fertilizer. Results from the study showed that grain production was lower in the 5 and 15 t ha‐1 SP treatments compared to the control in soil A probably due to a potassium (K) deficiency. Increasing application rat...

ESTIMATING SHORT- AND MEDIUM-TERM AVAILABILITY TO CEREALS OF NITROGEN FROM ORGANIC RESIDUES

BACKGROUND Espresso coffee grounds constitute a residue which is produced daily in considerable amounts, and is often pointed out as being potentially interesting for plant nutrition. Two experiments (incubations and field experiments) were carried out to evaluate the potential nitrogen (N) and phosphorus (P) supply for carrot (Daucus carota L.), spinach (Spinacea oleracea L.) and lettuce (Lactuca sativa L.) nutrition. RESULTS Immobilisation of nitrogen and phosphorus was detected in all the incubations and, in the field experiments, germination and yield growth were decreased by the presence of espresso coffee grounds, in general for all the species studied. CONCLUSION The study showed an inhibition of N and P mineralisation and a reduction of plant germination and growth. Further research is required to determine whether this is related to the immobilising capacity of the residue or possibly due to the presence of caffeine.

Effects of cadmium on sorghum plants (Sorghum vulgare Pers.) cultivated on soiless culture

Overused soil resources and the build-up of organic residues from industrial processes have resulted in increased risk of environmental contamination. Recycling of organic residues from industry by incorporation into agricultural soil, can provide valuable organic amendment as well as supply nutrients to crops. The effect of applying organic amendments to an agricultural sandy soil on the nitrogen nutrition of wheat (Triticum aestivum L.) and residual effects on the growth of a following maize crop (Zea mays, L.), were assessed under semi-controlled environmental conditions and were compared to nitrogen mineralization prediction obtained from an aerobic incubation. Six different organic residues (composted municipal solid waste, secondary pulp-mill sludge, hornmeal, poultry manure, the solid phase from pig slurry and composted pig manure) were added to a Cambic arenosol, incubated or used in pot experiments, to evaluate and try to predict the availability to crop plants of nitrogen released from these materials. Poultry manure was the most effective amendment in making nitrogen available and enhancing nitrogen uptake by wheat plants resulting in greater dry matter yield. The dried solid phase from pig slurry and hornmeal were also beneficial to wheat growth. There was a greater recovery of nitrogen (N), from organic materials studied, by a maize crop. Poultry manure was the residue that provided a greater residual effect on N supply to maize.

Potential mineralization of nitrogen from organic wastes to ryegrass and wheat crops

To evaluate the effect of cadmium (Cd) on growth and absorption of Cd and other elements by sorghum plants (Sorghum vulgare Pers.), a soiless experiment was carried out. Dry matter yield was significantly affected by Cd concentration in nutrient solution greater than 1.0 mg L-1. Cd content in plants significantly increased with the increasing additions of Cd to growth medium. Cadmium stimulated the absorption of Mg, Na, Cu and Fe and decreased Zn and Mn contents in sorghum. Ca and K in the plants were not affected by the presence of Cd.