Towards Sustainable Dairy Production in Argentina: Evaluating Nutrient and CO2 Release from Raw and Processed Farm Waste

Mineralization studies are the first step in determining the usefulness of an amendment such as fertilizer, and are essential to creating guidelines for dairy waste management to help producers make informed decisions. Our goal was to assess the effects of dairy raw, composted, and digested manure amendments on C, N, and P mineralization to evaluate the feasibility of their in-farm production and use as organic fertilizers. The liquid and solid fractions of dairy effluent (LDE, SDE), dairy effluent digestate (DED), onion–cattle manure digestate and compost (OCMD, OCMC) were characterized by chemical and spectroscopic methods. Soil microcosms with LDE, SDE, DED, OCMD and OCMC and the C, N and P mineralization were determined periodically. Elemental and structural differences among amendments led to contrasting profiles of C, N, and P mineralization, and thus to differences in nutrient availability, immobilization, and CO2 emission. All processed materials were more stable than untreated waste, reducing C emissions. Digestates showed net C immobilization, and supplied the highest levels of available N, creating a relative P deficit. Instead, the compost supplied N and P via mineralization, producing a relative P excess. Future studies should aim at evaluating fertilization strategies that combine both kinds of amendments, to exploit their complimentary agronomic characteristics.

The Effect of Some Soil Amendments (Manure and Biochar) on the Bioaccumulation Capacity of Hexavalent Chromium by Two Species of (Salicornia Persica) and (Salicornia Perspolitana) From Contaminated Soil

Heavy metals are among the most dangerous contaminants in the environment. Application of organic compounds and plant species with the ability to accumulate and stabilize heavy metal in their organs is the best option for remediation of these elements in the soil. Therefore, this study aimed to investigate the effects of manure and biochar on the accumulation of heavy metals by Salicornia species. Two species of Salicornia ,including S. persica and S. perspolitana, were cultivated outdoor in experimental pots. The effects of experimental treatments ,including hexavalent chromium concentrations, manure ,and biochar on the two studied species, were investigated. The results indicated a significant effect (P < 0.05) of biochar on the accumulation of heavy metals by two species ,S. persicaand S. perspolitana, so that chromium concentrations in the roots and shoots were 258 and 5.41 mg/kg, respectively. Also, chromium accumulations under manure treatments in the roots and shoots were 334.34 and 9.79 mg/kg, respectively. Plant dry weight and height for both species in manure treatment were higher than control and biochar treatments. S. persica showed higher growth than S. perspolitana species. The content of photosynthetic pigments in both S.persica and S. perspolitana species under biochar treatment was higher than control and manure treatments. In general, one can conclude that the accumulation of chromium in S. perspolitana was higher than in S. persica ,and the application of biochar and manure amendments could stabilize chromium in soil and reduce chromium accumulation in both S. persica and S. perspolitana species.

Potential of Sentinel-2 Satellite Images for Monitoring Green Waste Compost and Manure Amendments in Temperate Cropland

Increasing attention has been placed on the agroecological impact of applying exogenous organic matter (EOM) amendments, such as green waste compost (GWC) and livestock manure, to agricultural landscapes. However, monitoring the frequency and locality of this practice poses a major challenge, as these events are typically unreported. The purpose of this study is to evaluate the utility of Sentinel-2 imagery for the detection of EOM amendments. Specifically, we investigated the spectral shift resulting from GWC and manure application at two spatial scales, satellite and proximal. At the satellite scale, multispectral Sentinel-2 image pairs were analyzed before and after EOM application to six cultivated fields in the Versailles Plain, France. At the proximal scale, multi-temporal spectral field measurements were taken of experimental plots consisting of 14 total treatments: EOM variety, amendment quantity (15, 30 and 60 t.ha−1) and tillage. The Sentinel-2 images showed significant spectral differences before and after EOM application. Exogenous Organic Matter Indices (EOMI) were developed and analyzed for separative performance. The best performing index was EOMI2, using the B4 and B12 Sentinel-2 spectral bands. At the proximal scale, simulated Sentinel-2 reflectance spectra, which were created using field measurements, successfully monitored all EOM treatments for three days, except for the buried green waste compost at a rate of 15 t.ha−1.

Nitrogen and phosphorus control carbon sequestration in agricultural ecosystems: modelling carbon, nitrogen, and phosphorus balances at the Breton Plots with ecosys under historical and future climates

Perennial legumes in crop rotations increase soil C sequestration from greater productivity with N2 fixation. Here, we corroborated increases in soil organic carbon (SOC) and harvests modelled in 5 yr wheat–oats–barley–alfalfa/brome–alfalfa/brome (5Y) vs. 2 yr wheat–fallow (WF) rotations with those measured from 1929 to 2018. Harvest and SOC gains of 100–150 g C m−2 yr−1 and 15–25 g C m−2 yr−1 were modelled and measured in 5Y vs. WF rotations with different fertilizer and manure amendments. Modelled gains were closely related to annualized rates of N2 fixation by alfalfa of 8–10 g N m−2 yr−1. However, N2 fixation also drove increases in modelled N2O emissions of ca. 0.06 g N m−2 yr−1, which partially offset gains in SOC. Gains in harvest, SOC, and N2O emissions of 60–90 g C m−2 yr−1, 15 g C m−2 yr−1, and 0.05 g N m−2 yr−1 were modelled and measured in both rotations with amendments of N + P relative to unamended treatments. Harvest and SOC gains were smaller, and leaching and N2O losses larger, with amendments of N without P. After 100 yr of RCP 8.5 climate change, harvests in WF changed little from those in baseline runs, whereas those in 5Y rose with N + P because of increased N2 fixation. SOC declined in WF with all amendments and could only be raised in 5Y with N + P amendments. These model findings indicated the importance of N2 fixation and P amendments in determining responses of agroecosystem productivity and C sequestration to climate change.

EARLY GROWTH RESPONSE AND NUTRIENTS QUALITY OF FIG (Ficus carica L.) PLANTED ON BRIS SOIL EFFECTED BY CHICKEN MANURE AMENDMENTS

Allah S.W.T swears by the fig tree (Sura’ 95, al-Tin) in the holy Quran, for its values and practices. Recently, the fig tree (Ficus carica L.) has been introduced in Malaysia’s tropical weather as it grows well with maximum activity. Its root favors a well-drained type of soil, and since BRIS (Beach Ridges Interspersed with Swales) are dominated by sandy texture with proper water percolation, it has a high potential for fig planting. However, BRIS is known to have low nutrient holding capacity but can be improved with organic amendments. This study was carried out to determine the effects of various rates of chicken manure as amendments in improving the BRIS soil health for the growth of fig trees. The BRIS soil was amended with different rates of 10% (T2), 20% (T3), 30% (T4), and 50% (T5) of chicken manure and 0% (T1) as control. Three months old saplings were propagated through hardwood cuttings of variety BTM6 with five replications in each treatment. The growth response and nutrients quality of the fig trees were observed biweekly for three months after the transplant, and the nutrient contents of amended and non-amended showed significant differences at p<0.05. The survivability of the trees was 100%, and a significant difference was found between the treatments. BRIS soil with 40% chicken manure amendments (T4) showed superlative growth response with the highest number of branches, leaves, and fruits, thus provide higher yield production as compared to other treatments. From this study, BRIS soil that is known to be problematic can be improved with correct rates of organic amendments and can be used for fig cultivation.