Fertility Patterns Research Articles

The relationship between staying at home during the pandemic and the number of conceptions: A national panel data analysis.

hether the COVID-19 pandemic has changed fertility patterns is still an open question, as social isolation for long periods can impact the number of conceptions in many ways. We combine administrative data on all recent births in Brazil with daily data on individual location to estimate the relationship between the share of individuals staying close to their homes in each week and the number of conceptions in that same week, comparing municipalities with different social isolation patterns during the first semester of 2020. We find that conceptions unequivocally decline when social isolation increases. The effect is stronger for women who are between 21 and 25 years old and more educated, as well as for richer, larger, and more urban municipalities. COVID-19 is likely to change fertility across countries depending on the behavior of the population and on the lock-down measures implemented to fight the pandemic.

A Novel Macro Perspective on Family Dynamics: The Contribution of Partnership Contexts of Births to Cohort Fertility Rates

AbstractPartnering behavior is central to understanding fertility. Influential concepts, including singlehood, serial monogamy, and multiple‐partner fertility, are frequently used to analyze partnering and childbearing dynamics. These concepts are evoked to understand individual and population‐level patterns but are mainly analyzed at the individual level. We propose a measure for gauging the interplay between partnerships and childbearing at the population level, namely cohort fertility rates (CFR) as the sum of births under various partnership contexts. Surprisingly, demographers rarely measure and do not have a clear picture of the extent to which childbearing in different partnership contexts contributes to completed fertility. We analyze Finnish register data to decompose CFR into births across union status, union order, and reproductive partner order. Contrary to the discourse of partnering in the Nordics, births within first unions to first reproductive partners account for about two‐thirds of CFR. Births in higher‐order unions to first reproductive partners account for one‐fifth. Single births and births with higher‐order reproductive partners have a modest impact. This ranking holds across sex and educational level. We argue that the proposed measures offer a novel appraisal of population‐level implications of partnerships and childbearing dynamics and provide an opportunity to understand cross‐country variation in fertility patterns.

Seasonal patterns in newborns’ health: Quantifying the roles of climate, communicable disease, economic and social factors

Poor health at birth can have long-term consequences for children’s development. This paper analyses an important factor associated with health at birth: the time of year that the baby is born, and hence seasonal risks they were exposed to in utero. There are multiple potential explanations for seasonality in newborns’ health. Most previous research has examined these in isolation. We therefore do not know which explanations are most important – and hence which policy interventions would most effectively reduce the resulting early-life inequalities. In this paper, I use administrative data to estimate and compare the magnitudes of several seasonal risks, seeking to identify the most important drivers of seasonality in the Northern Territory of Australia, a large territory spanning tropical and arid climates and where newborn health varies dramatically with the seasons. I find that the most important explanations are heat exposure and disease prevalence. Seasonality in food prices and road accessibility have smaller effects on some outcomes. Seasonal fertility patterns, rainfall and humidity do not have statistically significant effects. I conclude that interventions that protect pregnant women from seasonal disease and heat exposure would likely improve newborn health in the Northern Territory, with potential long-term benefits for child development. It is likely that similar impacts would apply in other locations with tropical and arid climates, and that, without action, climate change will accentuate these risks.

Effects of long-term fertilization patterns on bacterial community structure and soil nutrients in dryland of yellow soil.

Understanding the responses of soil bacterial community to long-term fertilization in dryland of yellow soil could provide theoretical basis for establishing scientific fertilization system and cultivating healthy soil. Based on a 25-year long-term fertilization experiment on yellow soil, we collected soil samples from 0-20 cm layer under different fertilization treatments: no fertilization (CK), balanced application of N, P and K fertilizers (NPK), single application of organic fertilizer (M), combined application of constant organic and inorganic fertilizer (MNPK), and 1/2 organic fertilizer instead of 1/2 chemical fertilizer (MNP). Illumina MiSeq high-throughput sequencing technology was used to examine the effects of different fertilization patterns on soil bacterial community structure and soil nutrient content. The main driving factors of soil bacterial community were explored. The results showed that soil pH and organic matter content under treatments with organic fertilizer increased by 11.4%-13.5% and 28.8%-52.0%, respectively, compared to that under NPK treatment. Long-term fertilization did not affect soil bacterial α diversity, but significantly affected soil bacterial β diversity. Compared with CK and NPK treatment, treatments of M, MNP, and MNPK significantly changed soil bacterial community structure, and increased the relative abundance of Fusobacteria and Anaerobes. Four fertilization treatments increased the relative abundance of Bacteroidetes, and decreased the relative abundance of Actinomyces and Campylobacter, compared to CK. Soil pH was the most important factor affecting soil bacterial community structure. Fertilization-stimulated rare microbial taxa (Pumilomyces and Anaerobes) were more sensitive to changes in different environmental factors and were the main drivers of the formation of community versatility. In conclusion, organic fertilizer improved soil properties and fertility and changed soil bacterial community structure, which are conducive to cultivating healthy soil.

Changes in Policy, Changes in Fertility? An Examination of Changes in Fertility Aspirations in China

Fertility policies in China have changed substantially over recent years, with the intention of allowing individuals to bear more children and, thereby, to increase the total fertility rate. Using a sample of young adults, this study examines changes in fertility aspirations (the desired number of children, and the timing of first birth) across the three fertility policy periods (One-Child, Two-Child, and Three-Child). The results show that both young females and males increasingly prefer fewer children, and a later age at first birth. Both parental and peer factors are shown to significantly affect fertility aspirations, yet individual factors, such as gender attitudes and pronatal beliefs, yield stronger associations. The implications of the findings, along with the possible future of fertility patterns in China, are discussed with the developmental paradigm.

The Changing Trends and International Comparison of Chinese Women's Fertility Pattern under Low Fertility Level

Using data from Chinese national population censuses and 1% population sampling surveys from 2000 to 2020, by analyzing the age-specific fertility contribution rate curve, the Mean age at birth, the Standard deviation in Mean age at birth in different years, and comparing with the transformation process of fertility pattern in developed countries, this paper analyses the changing trends in Chinese women's fertility pattern under low fertility level. The results find that under low fertility level, the growth rate of Chinese women's Mean age at birth turns from fast to slow, the dispersion of fertility pattern rises first and then falls, and the distribution of child-bearing age is overall postponed. Compared with developed countries, the transformation of Chinese women's fertility pattern started late, changed quickly, and fluctuated greatly, from significantly lagging behind the general transformation process of fertility pattern in developed countries to rapidly approaching the average level of fertility pattern in developed countries. The adjustment of Chinese fertility policy has had a significant impact on the fertility pattern, leading to a turning point in the changing trends of the fertility pattern after 2010. With the development of economy and society and the continuous adjustment of fertility policy, the future fertility pattern of Chinese women may show trends that women's child-bearing age will continue to rise, but the dispersion of fertility pattern will slightly decline in fluctuations.

Ethnic Variation in Fertility Preferences in Sub-Saharan Africa

Research focusing on the role of ethnicity in shaping fertility preferences in sub-Saharan Africa (SSA) has been largely restricted to small-scale studies within specific groups, regions or countries, which makes it difficult to gain insight into the overall effects of ethnicity on fertility in the region. This study provides a broad comparative analysis of the variation in preferred family size among ethnic groups covering the whole SSA subcontinent. The relationship between ethnicity and family size preferences is analyzed for 500,000 women from 181 ethnic groups in 24 sub-Saharan countries using data from the Demographic and Health Surveys and via multilevel Poisson regression analyses. Fertility preferences vary considerably across ethnic groups. Major factors explaining this are gender-related cultural characteristics and educational level at the group level. Interaction analyses showed that the size and direction of these effects are moderated by the women’s individual characteristics. The findings make clear that someone’s ethnic background should be taken into account when looking at fertility patterns and designing policies aimed at changing fertility patterns in the SSA context.

Descendants over 300 years: Marital fertility in five lineages in Qing China

AbstractThis paper studies the marital fertility—broadly defined as the ratio of live births to married women—of five Chinese lineages since the 17th century, mainly in the Qing Dynasty (1644–1911). The results demonstrate a unique pattern of Chinese marital fertility by exploiting new genealogical data and studying more than 50,000 individuals from five lineages. Contrary to the conventional wisdom, the marital fertility rates in the period were moderate. On the other hand, in line with the classic ideas, this paper finds no clear indication of two fertility controls within marriages, parity‐dependent early stopping and longer spacing.

Combining multi-isotope technology, hydrochemical information, and MixSIAR model to identify and quantify nitrate sources of groundwater and surface water in a multi-land use region.

Accurate identification of nitrate(NO3-) sources is the premise of non-point source pollution control in watersheds. The multiple isotope techniques (δ15N-NO3-, δ18O-NO3-, δ2H-H2O, δ18O-H2O), combined with hydrochemistry characteristics, land use information, and Bayesian stable isotope mixing model (MixSIAR), were used to identify the sources and contributions of NO3- in the agricultural watershed of the upper Zihe River, China. A total of 43 groundwater (GW) and 7 surface water (SFW) samples were collected. The results showed that NO3- concentrations of 30.23% GW samples exceeded the WHO maximum permissible limit level, whereas SFW samples did not exceed the standard. The NO3- content of GW varied significantly among different land uses. The averaged GW NO3- content in livestock farms (LF) was the highest, followed by vegetable plots (VP), kiwifruit orchards (KF), croplands (CL), and woodlands (WL). Nitrification was the main transformation process of nitrogen, while denitrification was not significant. Hydrochemical analysis results combined with NO isotopes biplot showed that manure and sewage (M&S), NH4+ fertilizers (NHF), and soil organic nitrogen (SON) were the mixed sources of NO3-. The MixSIAR model summarized that M&S was the main NO3- contributor for the entire watershed, SFW, and GW. For contribution rates of sources in GW of different land use patterns, the main contributor in KF was M&S (contributing 59.00% on average), while M&S (46.70%) and SON (33.50%) contributed significantly to NO3- in CL. Combined with the traceability results and the situation that land use patterns are changing from CL to KF in this area, improving fertilization patterns and increasing manure use efficiency are necessary to reduce NO3- input. These research results will serve as a theoretical foundation for controlling NO3- pollution in the watershed and adjusting agricultural planting structures.

Pattern and trends of the total and age-specific fertility rates during 1990–2018 in Pakistan

BackgroundPakistan has an inadequate vital event registration system, leading to fewer than half of all births being registered, and this issue is further exacerbated by systematic recall errors and omission of births. This study aims to evaluate direct and indirect methods of fertility estimation to analyze the trends and patterns of fertility rates in Pakistan from 1990 to 2018.Design/methodology/approachIndirect methods are utilized in this study to evaluate the direction and extent of changes in total and age-specific fertility rates, and these findings are compared to direct estimates. The study draws data on livebirths from four waves of the Pakistan Demographic and Health Survey that took place between 1990 and 2018. To ensure the quality of data, graphical methods and Whipple and Myers indices are employed. Additionally, the Brass Relational Gompertz model was used to analyze the data.ResultsThe Relational Gompertz model revealed that total fertility rates (TFRs) were higher than direct estimates by 0.4 children and age-specific fertility rates (ASFR) were higher for all age groups except the oldest. The difference was more significant among younger women aged 15–24, and less so for age groups 29 and above. The gap in estimated fertility between direct and indirect methods decreased with age.ConclusionThe indirect method is an invaluable tool in situations where direct measurement of fertility rates is challenging or impossible. By utilizing this method, policymakers can gain important insights into the fertility patterns and trends of a population, which is crucial for making informed decisions on fertility planning.

Stability and change in male fertility patterns by cognitive ability across 32 birth cohorts.

The relationship between cognitive ability (CA) and childbearing remains unsettled. Using Norwegian administrative registers with population coverage, we study how male lifetime fertility patterns differ across cognitive score groups, and how these changed across the 1950-1981 birth cohorts, covering a period characterized by rapid social and economic change. The analyses reveal systematic differences in fertility and fertility timing across CA groups, with high scoring males having delayed but ultimately higher fertility than lower scoring males. This pattern remains stable over time despite strong trends towards delayed and reduced fertility. The overall positive relationship between CA and fertility is primarily driven by high rates of childlessness in the lowest scoring group, with low-scoring males showing higher rates of parity progression at higher parities.

Fertility patterns and sex composition preferences in immigrant–native unions in Sweden

Intermarriage between immigrants and native individuals highlights the need to study childbearing as a joint decision of couples, because fertility preferences are likely to differ for the two partners involved. This study focuses on Sweden, where the majority population holds a relative preference for daughters but many immigrants come from countries with son preferences. Using longitudinal registers for the period 1990–2009, I analyse third-birth risks according to the sex composition of previous children and type of union. Doing so allows the study of preferences from behavioural data: couples with a daughter preference, for example, are more likely to have another child if their two previous children were boys. Results show that third-birth risks tend to be higher in unions between Swedish women and immigrant men, whereas unions between Swedish men and immigrant women tend to exhibit lower third-birth risks. Son preferences are rarely realized in intermarriages.

Study on the Delay of Marriage and Childbirth of Wenzhou Ouhai Population and its Influencing Factors

Marriage and fertility are important topics in population studies, where individuals establish families through marriage and carry on life through childbearing within the family. Marriage and fertility microscopically measure the life course of individuals and macroscopically reflect the marriage and childbearing attitudes and marriage and childbearing culture of population groups. Marriage and fertility patterns consisting of marriage and fertility patterns are usually described and analyzed through indicators such as average age at first marriage and average age at first childbirth. data from the seventh population census of ouhai district in 2020 and fertility data from the health commission show that the average age at first marriage for women in ouhai district is 27.68 years old and the average age at first childbirth is 28.57 years old, while the average age at first marriage and the average age at first childbirth for women in ouhai district at the sixth population census in 2010 was 23.11 years old and The average age of first marriage and first childbirth of women in Ouhai District was 23.11 years old and 25.40 years old respectively in the sixth census in 2010, an increase of 4.57 years and 3.17 years respectively in 10 years. The delay of marriage and childbirth of Ouhai District population is more significant. In order to understand the willingness of Ouhai population to marry and give birth, and to serve the long-term balanced development of the population, at the request of Ouhai District Bureau of Statistics, the research group carried out a special study on "the delayed characteristics of marriage and childbirth of Ouhai population and its influencing factors". Through a comprehensive and in-depth analysis and study of the sixth and seventh national census data and health commission fertility-related data, (the number of people in the census long form quoted in the article refers to the number of sample survey, not the actual number. The total number of people in Ouhai District in the seventh census is 963,238, and the number of people in the long-form sampling survey is 93,713, with a sampling ratio of 9.73%; the total number of people in Ouhai District in the sixth census is 996,870, and the number of people in the long-form sampling survey is 94,732, with a sampling ratio of 9.50%. (The two census sampling ratio is slightly different) The survey results show that: the Ouhai District citizens delayed marriage and childbirth, the willingness to have children is not high, by the education level, occupational factors, such as the influence of the larger, need to promote the implementation of existing policies at the same time, the system to introduce education, childbirth, parenting, housing, medical and other supporting measures to promote residents to marry at the right age, improve the willingness of residents to have children.

Trends and projections of ovarian cancer incidence in Hong Kong: A population-based study.

This study analyzed the incidence of ovarian cancer in Hong Kong and its association with age, calendar period and birth cohort, made projections through 2030, and attributed differences in new cancer cases to demographic and epidemiologic changes. Incidence data for ovarian cancer were obtained from the Hong Kong Cancer Registry. We employed the age-period-cohort modeling approach to investigate the association between ovarian cancer incidence and age in Hong Kong women, with particular emphasis on examining the changing trends of period and cohort effects on incidence. We projected the incidence of ovarian cancer in Hong Kong between 2018 and 2030 and attributed the rise in new cancer cases to epidemiologic and demographic shifts. Between 1990 and 2017, a total of 11 182 women were diagnosed with ovarian cancer in Hong Kong. Crude and age-standardized rates increased from 8.2 and 7.8 per 100 000 person-years to 16.3 and 11.5 per 100 000 person-years, respectively. New cases of ovarian cancer rose from 225 in 1990 to 645 in 2017. We observed an increased risk of ovarian cancer throughout the study period and in the post-1940 birth cohort. The projected incidence rate and new cases of ovarian cancer are expected to continue growing due to demographic and epidemiologic changes such as fertility patterns and lifestyle factors, with an estimated 981 cases in 2030. The period risk and cohort risk of ovarian cancer among Hong Kong women is increasing. Demographic and epidemiologic changes may continue to increase ovarian cancer incidence and new cases in Hong Kong.

Understanding the perspective of women who use the Billings Ovulation Method®: a focus group study

BackgroundThe Billings Ovulation Method®(the Billings Method) is a fertility awareness-based method (FABM) of family planning that relies on the observation of patterns of fertility and infertility based on vulvar sensations and appearance of discharges. This allows people to choose when to have intercourse, depending on whether they want to avoid or achieve pregnancy. Few studies have documented user experiences with FABMs.MethodsWe conducted four virtual focus groups (FGs) in May and June 2021 with current adult women users of the Billings Method. We asked questions about users' reasons for selecting a FABM and the Billings Method, positive experiences and challenges learning and using the Billings Method, and suggestions for improving the user experience. We performed a content analysis of the transcribed FGs to explore key themes from the discussions. COREQ guidelines were followed.ResultsTwenty women between the ages of 23 and 43 participated in the FGs. Reasons women described choosing a FABM included to follow religious beliefs, to avoid side effects of hormonal contraception, and/or to learn more about their bodies. Reasons for selecting the Billings Method included perceiving it as more precise and easier to understand than other FABMs, having a scientific basis, and being recommended by family and friends. Experiences related to learning and using the Billings Method were mainly positive. They included finding the method easy to use and learn, successfully using it to either postpone or achieve a pregnancy and increasing their awareness of their bodies. Challenges for participants included the inherent learning curve for identifying sensations at the vulva and the required periods of abstinence. Participants provided suggestions and recommendations for improving users' experience, including raising awareness of the Billings Method among healthcare providers.ConclusionsUsers of the Billings Method expressed an overall positive experience when learning and using it for family planning and body awareness. Some challenges were identified that offer opportunities to improve how the Billings Method is taught and delivered. These findings can also enhance healthcare providers' interactions with FABM users, including those of the Billings Method.

Harvestify - Crop Disease Detection and Fertilizer Suggestion using CNN

Abstract: Farmers in many parts of India are having trouble growing crops because of the climate and soil. There could be no genuine assistant available to assist them with encouraging the right sorts of plants using current advancement. Due to illiteracy, farmers may not be able to benefit from advances in agricultural science and continue using human methods. This makes it difficult to achieve the desired yield. For instance, improper fertilization or unintentional rainfall patterns may be the cause of crop failure. In such circumstances, picking crops that are suitable for the soil's current conditions and the anticipated rainfall during planting would be the best course of action. Thus, we are presenting an information mining-based "Soil-Based Profile Profiling Framework." In light of the rancher's region's precipitation and soil input boundaries (NPK and pH), we provide a list of possible yields. Additionally, it suggests fertilizer that can be utilized to increase crop yields and enhance the soil's quality. The growing problem of crop failure is the focus of this desktop application

一次性机械化穴施缓释复合肥对玉米产量和养分吸收的影响

Currently, maize production in China suffers from many problems, such as excessive fertilizer application, inefficient fertilizer use, and insufficient agricultural labour. The effect of one-time mechanical point-applied fertilization of controlled-release compound fertilizer in the root-zone on yield and nutrient uptake was investigated to explore efficient fertilization patterns for fertilizer decrease and yield increase in maize. The selected fertilizer was a controlled-release granular fertilizer (24-6-10 for N-P2O5-K2O) with six treatments in the application program: 1) no fertilizer (CK); 2) application of a one-time banding fertilizer (BDP) 5 cm off the seeds between rows and 10 cm deep; 3) application of a one-time point-applied fertilization (RZF) 5 cm off seed in the row and 10 cm deep; 4) application of a one-time point-applied fertilization (90% RZF) 10% fertilizer reduction 5 cm off seed in the row and 10 cm deep; 5) application of a one-time point-applied fertilization (80% RZF) 20% fertilizer reduction 5 cm off seed in the row and 10 cm deep; 6) application of a one-time point-applied fertilization (70% RZF) 30% fertilizer reduction 5 cm off seed in the row and 10 cm deep. The results showed that RZF increased yield by 5.84% over BDP, and the difference was significant, indicating that mechanized point-applied fertilization of fertilizer can replace manual point-applied fertilization application operations and achieve increased crop yield. The agronomic utilization rate of fertilizer of 12.35% and the bias productivity of 5.31% were higher in RZF than in BDP, and the differences were significant, indicating that one-time mechanical point-applied fertilization in the root zone significantly improved fertilizer utilization and reduced fertilizer loss.

Fertility differential, public policy, and development

In the early stages of development, income and fertility across households are positively associated. However, in more developed stages, this association is negative or hump-shaped. Why does the income–fertility relationship within economies change with development? This study focuses on the role of public policy in this issue. We demonstrate that the interaction between changes in public policy and economic development generates a historical UK fertility pattern.

The value, diagnostic efficacy and clinical significance of functional magnetic resonance imaging in evaluating the efficacy of neoadjuvant chemotherapy in patients with triple negative breast cancer.

Breast cancer (BC) is a common malignant tumor in female. In recent years, with the change of fertility pattern and lifestyle, the incidence of breast cancer is increasing year by year, seriously endangering the health and life of women. MRI is suitable for follow-up evaluation of the course of neoadjuvant chemotherapy in LABC, but there are few related studies and reports. Based on the above background, it is necessary to further evaluate the value of functional magnetic resonance imaging in neoadjuvant chemotherapy in patients with triple negative breast cancer, so as to lay a theoretical foundation for the popularization and application of this detection method. Based on this, this study was to explore the value, diagnostic efficacy and clinical importance of functional magnetic resonance imaging in evaluating the efficacy of neoadjuvant chemotherapy in patients with triple negative breast cancer. A total of 62 patients with triple-negative breast cancer who received neoadjuvant chemotherapy in our hospital from September 2017 to September 2022 were selected. To compare the differences of functional magnetic resonance imaging (fMRI) between effective and ineffective patients with neoadjuvant chemotherapy, the related data were statistically analyzed. There was no significant difference between the mode of tumor withdrawal and the pathological complete remission of tumor tissue (P>0.05). There was no significant difference in anti-Trop-2 antibody-drug conjugates (ADC) data before and after chemotherapy between over-expressed patients with human epidermal growth factor receptor-2 (HER-2) and non-over-expressed patients with HER-2 (P>0.05). The levels of ADC and Δ ADC in pathological complete remission patients after chemotherapy were significantly higher than those in non-pathological complete remission patients (P<0.05). Using the ΔADC value as the evaluation parameter, the pathological response of tumor tissue was classified as the "gold standard" to draw the ROC curve, the area under curve (AUC) was 0.673, the cut-off of ΔADC to evaluate the significant response of tumor tissue after chemotherapy was 1.418, the sensitivity of evaluating the efficacy was 71.9%, and the specificity was 55.0%. Functional magnetic resonance imaging (fMRI) has diagnostic value for neoadjuvant chemotherapy in patients with triple negative breast cancer. According to the change of ADC value, the curative effect can be predicted early and the treatment strategy can be adjusted in time.

Long-term different fertilization regimes impact on the fate of root-derived C and microbial community structure in paddy soil

It is known that fertilization pattern could alter soil nutrient and organic matter status. However, it is still unclear how photosynthesized C is distributed in rice–rhizosphere soil-microbial system and its influencing factors due to fertilization pattern and subsequent changes in soil fertility. This study examined the allocation of rice photosynthetic C in rice–rhizosphere soil–microbial systems and the changes in microbial community under three long-term fertilizer regimes. Rice was grown in soils with 8-year history of no fertilizer, inorganic fertilizer (NPK) or NPK fertilizer plus cattle manure (NPK + CM), and was pulse–labelled with 13CO2 at rice tillering stage. The results showed that 13C incorporation in rice-rhizosphere soil system was the highest in the NPK + CM treatment, increased by 489% and 28.9% compared to unfertilized control and the NPK alone. In the >2 mm aggregate fraction, the 13C enrichment was higher in NPK + CM compared to no-fertilized control and NPK treatments. Total PLFA and PLFA groups contents in all aggregate size fractions were the greatest in the NPK + CM treatment. Partial least squares path modelling analysis revealed that microbial community in large macroaggregate (>2 mm) was significantly (P < 0.05) affected by root properties, while soil fertility had a significant (P < 0.01) impact on microbial community in microaggregate (<0.25 mm). The redundancy analysis showed that soil parameters except soil alkali-hydro nitrogen (AN) significantly impacted the soil microbial communities. Through canonical variation partitioning analysis, soil available K was the most important factor leading to variance (11.4%) in microbial community composition. On the other hand, soil pH significantly (P < 0.05) affected the distribution of 13C in microbe community. More than 20% of 13C was incorporated into G– and G+ bacteria across all treatments. Overall, it was observed the NPK fertilizer plus cattle manure treatment was most conducive to retain C from root exudates in the rice-rhizosphere soil-microbial system.