Fertility Values among Women of Childbearing Age in Hunan Province, China: A Cross-Sectional Study

Background: China is facing with a crisis of the aging population. After the implementation of the latest fertility policy, the research on fertility related issues is urgent. Objective: The objective of this study is to explore the fertility values among women of childbearing age and the socio-demographic factors associated with it under the background of three-child policy, which is helpful to cope with the aging of the population. Methods: This study was conducted among 383 women of childbearing age who met the inclusion criteria using a general information questionnaire and the fertility values questionnaire from May to August 2021 in Hunan Province, China. Data were collected on the women’s socio-demographic characteristics and fertility values. The descriptive statistics, t-test and analysis of variance were used for data analysis. Results: The total mean score of the positive values was 43.55 ± 10.10, and that of the negative values was 50.87 ± 13.85. There were significant differences in the scores of the overall positive and negative values, as well as scores of each dimension (p The item mean score of the overall negative values (3.38 ± 0.93) was higher than that of the overall positive values (2.90 ± 0.67). Among the positive values, “emotional value” (4.26 ± 0.93) scored the highest, while “worrying about life changes” (3.88 ± 1.10) scored the highest among the negative values. There were significant differences in both the positive and negative values in terms of age, marital status, and “only-child” women or not (p Conclusion: The fertility values among women of childbearing age in Hunan Province were relatively negative, especially, excessive worries about life change since having a child, which may lead to further declines in fertility levels. Relevant support measures are urgently needed from the government to adapt to the three-child policy.

Wheat straw pretreatment with KOH for enhancing biomethane production and fertilizer value in anaerobic digestion

Wheat straw biodegradability during anaerobic digestion was improved by treatment with potassium hydroxide （KOH） to decrease digestion time and enhance biomethane production and fertility value. KOH concentrations of 1% （KI）, 3% （[（2）, 6% （K3） and 9% （l（4） were tested for wheat straw pretreatment at ambient temperature with a C：N ratio of 25：1.86% of total solids （TS）, 89% of volatile solids （VS） and 22% of lignocellulose, cellulose and hemi- cellulose （LCH） （22%） were decomposed effectively with the wheat straw pretreated by 6% KOH. Enhanced bio- gas production and cumulative biomethane yield of 258 ml. （g VS）-1 were obtained increased by 45% and 41% respectively, compared with untreated wheat straw. Pretreated wheat straw digestion also yielded a digestate with higher fertilizer values potassium （l 38%）, calcium （22%） and magnesium （16%）. These results show that TS, VS and LCH can be effectively removed from wheat straw pretreated with KOH, improving biodegradability biomethane production and fertilizer value.

Soil phosphorus dynamic, balance and critical P values in longterm fertilization experiment in Taihu Lake region, China

Phosphorus（P） is an important macronutrient for plant but can also cause potential environmental risk. In this paper, we studied the long-term fertilizer experiment（started 1980） to assess the soil P dynamic, balance, critical P value and the crop yield response in Taihu Lake region, China. To avoid the effect of nitrogen（N） and potassium（K）, only the following treatments were chosen for subsequent discussion, including： C0（control treatment without any fertilizer or organic manure）, CNK treatment（mineral N and K only）, CNPK（balanced fertilization with mineral N, P and K）, MNK（integrated organic manure and mineral N and K）, and MNPK（organic manure plus balanced fertilization）. The results revealed that the response of wheat yield was more sensitive than rice, and no significant differences of crop yield had been detected among MNK, CNPK and MNPK until 2013. Dynamic and balance of soil total P（TP） and Olsen-P showed soil TP pool was enlarged significantly over consistent fertilization. However, the diminishing marginal utility of soil Olsen-P was also found, indicating that high-level P application in the present condition could not increase soil Olsen-P contents anymore. Linear-linear and Mitscherlich models were used to estimate the critical value of Olsen-P for crops. The average critical P value for rice and wheat was 3.40 and 4.08 mg kg^（–1）, respectively. The smaller critical P value than in uplands indicated a stronger ability of P supply for crops in this paddy soil. We concluded that no more mineral P should be applied in rice-wheat system in Taihu Lake region if soil Olsen-P is higher than the critical P value. The agricultural technique and management referring to activate the plant-available P pool are also considerable, such as integrated use of low-P organic manure with mineral N and K.

Effect of substrate concentration on the bioleaching of heavy metals from sewage sludge

The effect of elemental sulfur concentration on bioleaching of Cu, Zn and Pb and loss of fertilizer value from sewage sludge was investigated in flasks by batch experiments. The results showed that the ultimate pH of sludges with 3—5 g/L of sulfur added was about 1.3 and the production of SO 2- 4 had good correlation with the elemental sulfur concentration. The sensitivity of removal efficiency of metals to sulfur concentration was: Pb>Cu>Zn. The sulfur concentration except for 3—5 g/L had significant effect on the solubilization of Cu, Pb and Zn. The highest solubilization efficiency for sludge with 3 g/L of sulfur was 87.86% for Cu, 32.72% for Pb and 92.14% for Zn, which could make the treated sludge easily meet the metal limitations for land application. The sulfur concentration of 3 g/L was enough for the solubilization of all three heavy metals. The influence of sulfur concentration on solubilization of total nitrogen and potassium from sludge was negligible, but that on solublization of total phosphorus was of great importance. The loss of nitrogen, phosphorus and potassium of sludge with 3 g/L of sulfur by bioleaching was 38.2%, 52.1% and 42.8% respectively, and the sludge still remained satisfactory fertilizer value after bioleaching.

Full utilization of nutrients in rice straw by integrating mushroom cultivation, biogas production, and fertilizer use

This study proposed an integrated process of Pleurotus ostreatus cultivation,anaerobic digestion of spent mushroom substrate(SMS),and fertilizer value evaluation of digestate for achieving multiple products and full utilization of nutrients in rice straw.The results showed that the cultivated mushroom yield from rice straw was 401 g/kg TS.Biomethane yield obtained from anaerobic digestion of SMS was 133.0 mL/g VS.The fertilizer value of the SMS based digestate reached the national standard of fertilizers from organic sources in China.Substance conversion of rice straw during the integrated process revealed that the process could achieve the full utilization of nutrients in the substrate.Energy assessment indicated that the process had the viability to be applied.Therefore,this study provided a feasible strategy to set up a complete recycling agricultural ecosystem.