Sheep manure application increases soil exchangeable base cations in a semi-arid steppe of Inner Mongolia

The long-term productivity of a soil is greatly influenced by cation exchange capacity（CEC）.Moreover,interactions between dominant base cations and other nutrients are important for the health and stability of grassland ecosystems.Soil exchangeable base cations and cation ratios were examined in a 11-year experiment with sheep manure application rates 0–1,500 g/（m2？a） in a semi-arid steppe in Inner Mongolia of China,aiming to clarify the relationships of base cations with soil p H,buffer capacity and fertility.Results showed that CEC and contents of exchangeable calcium（Ca2＋）,magnesium（Mg2＋）,potassium（K＋） and sodium（Na＋） were significantly increased,and Ca2＋ saturation tended to decrease,while K＋ saturation tended to increase with the increases of sheep manure application rates.The Ca2＋/Mg2＋ and Ca2＋/K＋ ratios decreased,while Mg2＋,K＋ and Na＋ saturations increased with increasing manure application rates.Both base cations and CEC were significantly and positively correlated with soil organic carbon（SOC） and soil p H.The increases of SOC and soil p H would be the dominant factors that contribute to the increase of cations in soil.On a comparison with the initial soil p H before the experiment,we deduced that sheep manure application could partly buffer soil p H decrease potentially induced by atmospheric deposition of nitrogen and sulfur.Our results indicate that sheep manure application is beneficial to the maintenance of base cations and the buffering of soil acidification,and therefore can improve soil fertility in the semi-arid steppes of northeastern China.

Biogas Production from Sheep Manure by a Simulated Underground Burial System Heated with Cascade-Controlled Solar Water Heated System, as an Indicator of Biomass Potential Contribution to Power Mix in Jordan

This paper is aimed at exploring the potential of implementing biomass as one of the sources of energy in Jordan using a simulated underground burial system. A controlled solar energy heated system was employed to maintain the anaerobic bioreactor at 40°C (mesophilic range). Sludge and wastewater, from wastewater treatment plant, was used as a seeding material to activate bacteria. Production of biogas was observed after 3 days of incubation. On average, a total of 94 liters/sample were obtained at 25°C and atmospheric pressure. This amount of gas is equivalent to 258 liters/kg (Standard Temperature and Pressure, STP) of sheep manure. The biogas average composition was 65% methane and 35% CO2, and the retention time was 35 days. Control runs at room temperature did not produce appreciable amount of biogas within the 35 days of incubation. The potential of biomass was studied based on estimated sheep manure production for the period of 2010-2016 in Jordan. The results obtained from the designed process were used to estimate the bio-gas production indicating a promising process to produce biogas by a burial bio-waste system. Upon scale-up of this process, biomass from different sources can be processed within short residence time, which will result in appreciable reduction of land fill areas and significant production of biogas that will contribute to the energy power mix in a non-oil producing country, such as Jordan.

Effects of biochar carried microbial agent on compost quality,greenhouse gas emission and bacterial community during sheep manure composting

Although composting is a very effective way to dispose agricultural wastes,its development is greatly limited by the low compost quality and greenhouse gas emissions.At present,there is a lack of effective means to solve these two problems simultaneously.Here,the effects of three additives of compound microbial agent,biochar and biochar carried microbial agent on the composting performance,nitrogen transformation,greenhouse gas and ammonia emissions,and bacterial communities were investigated in sheep manure composting during 28 days.Results showed that biochar carried microbial agent prolonged the thermophilic stage and promoted compost maturity.At the same time,it was confirmed by the increase of the decomposition of organic nitrogen and the transformation of NH_(4)^(+)-N to NO_(3)^(−)-N.Besides,adding biochar carried microbial agent decreased CH_(4),NH_(3) and N_(2)O emissions by 65.23%,42.05%and 68.64%,respectively.The gas emissions were mainly correlated to Chloroflexi,Myxococcota,Acidobacteriota,Firmicutes,and Gemmatimonadota.Redundancy analysis showed that EC and TKN were closely related to bacterial community.Therefore,biochar carried microbial agent is recommended as an effective additive to enhance compost quality and reduce gas emissions during sheep manure composting.

Effect of Organic and Chemical Fertilization on the Growth and Yield of Roselle Plants Hibiscus sabdariffa L.

This study was carried out during the growing season 2012-2013 at the fields of Agricultural Research Services in Sulaymaniyah Govemorate, to study the effect of chicken manure, sheep manure and chemical fertilizer NPK on growth, sepals, seeds yield and some chemical constituents of Roselle plants grown under Sulaymaniyah conditions. The experiment included several treatments as follows： sheep manure, 75% sheep ＋ 25% chicken, 50% sheep ＋ 50% chicken, 25% sheep ＋ 75% chicken, entire chicken manure, chemical fertilizer NPK and unfertilized control. The obtained results showed that all treatments of organic fertilization and NPK were significantly enhanced the vegetative growth parameters, sepals and concentration of anthocyanin of Roselle plants sepals. The treatment of （25% sheep ＋ 75% chicken） gave the best results： plant height （205.33 cm）, stem diameter （33.45 ram）, number of branches/plant （22.33）, total leaf area （3.29 m2）, root dry weight （56.81 g）, number of fruits/plant （110）, fresh weight of fruits （818.44 g） and dry weight of sepals （52.65 g）. But the highest concentration of anthocyanin was in the treatment of （75% sheep ＋ 25% chicken） （260.33 mg/100 g） and the lowest concentration of oxalic acid was found in the treatment of （50% sheep ＋ 50% chicken） （4.69 mg/100 g）. The results of this study showed that the use of （25% sheep ＋ 75% chicken） could enhance the vegetative growth and produce maximum yield of RoseUe calyx.