In order to grasp the research status of different fertilization modes in China s farmland more comprehensively, with papers in core journals of Chinese Peking University collected in CNKI database from 2003 to 2022 a...In order to grasp the research status of different fertilization modes in China s farmland more comprehensively, with papers in core journals of Chinese Peking University collected in CNKI database from 2003 to 2022 as the main research object, this paper analyzed the research status of different fertilization modes from the perspectives of annual number of published papers, published journals, keywords and highly cited papers applying the bibliometrics research method. This study provides reference for the research in this field.展开更多
Kiwifruit yield and quality and soil nutrients were investigated in a kiwifruit orchard after long-term fertilization to understand the relationship between kiwifruit growth and soil nutrition.Seven fertilization trea...Kiwifruit yield and quality and soil nutrients were investigated in a kiwifruit orchard after long-term fertilization to understand the relationship between kiwifruit growth and soil nutrition.Seven fertilization treatments with three replications were applied in a continuous four-year period,including no fertilizer(CK);phosphorus(P)and potassium(K)fertilizers(PK);N and K fertilizers(NK);N and P fertilizers(NP);N,P and K fertilizers(NPK);1.5 times of N,P and K fertilizers(1.5NPK);and chemical fertilizers plus swine manure(NPKM).Fertilization increased kiwifruit yield at the rate of 450 kg N/hm^(2),225 kg P2O5/hm^(2),300 kg K2O/hm^(2).The average yield decreased in a descending order for NPKM(44.6 t/hm^(2)),1.5NPK(42.6 t/hm^(2)),NPK(42.0 t/hm^(2)),NK(38.0 t/hm^(2)),NP(36.7 t/hm^(2)),PK(36.4 t/hm^(2))and CK(34.1 t/hm^(2)).The sugar to acid ratio(S:A)was the highest(10.9)in 2012,and the soluble sugar increased by 15.7%after four-year NPKM fertilization.The NPKM fertilization also significantly increased the vitamin C,soluble solid and firmness.The soil organic carbon contents at 0-20 cm,20-40 cm and 40-60 cm in depth under the NPKM treatment were 27%,29%and 139%higher than that of the CK treatment,respectively.The available N contents at 0-20 cm,20-40 cm and 40-60 cm in depth in the 1.5NPK treatment were 180%,114%and 133%higher than that in the CK treatment,respectively.Balanced fertilization with N,P,K and organic manure is important to soil fertility,which may increase yield and improve quality in field-grown kiwifruit orchard.展开更多
We focus on a small but growing segment of the U.S.population,those who identify as Chinese,Japanese and Korean(CJK),and compare CJK fertility to other race/ethnic groups in the United States.CJK women in the U.S.exhi...We focus on a small but growing segment of the U.S.population,those who identify as Chinese,Japanese and Korean(CJK),and compare CJK fertility to other race/ethnic groups in the United States.CJK women in the U.S.exhibit a distinct,pervasive,and persistent pattern of late and low fertility with nearly all births occurring within marriage;this pattern displays a strong parallel to their counterparts in their countries of origin.To accompany this description,we offer a perspective on fertility difference that has broad applicability and that does not consistently predict that differences will disappear/remain.This discussion unites the literature on assimilation,segmented assimilation and pluralistic outcomes and processes.We also discuss the possible implications of these findings for country level policies to increase fertility.Most generally,these discussions are a corrective to demographer’s penchant for predicting secular change and convergence.展开更多
基金Supported by Undergraduate Training Program for Innovation and Entrepreneurship of Guizhou Province(S202310664011)Natural Science Research Project of Guizhou Provincial Department of Education(QJJ[2022]067,QJJ[2023]043)Teaching Content and Curriculum System Reform Project of Colleges and Universities in Guizhou Province(GZJG20220776)。
文摘In order to grasp the research status of different fertilization modes in China s farmland more comprehensively, with papers in core journals of Chinese Peking University collected in CNKI database from 2003 to 2022 as the main research object, this paper analyzed the research status of different fertilization modes from the perspectives of annual number of published papers, published journals, keywords and highly cited papers applying the bibliometrics research method. This study provides reference for the research in this field.
基金IPNI(International Plant Nutrition Institute),2011collaborative technology innovation in Shaanxi Province(QBXT-Z(P)-15-5)Key Laboratory for Agricultural Environment,Ministry of Agriculture Open Foundation(2015)。
文摘Kiwifruit yield and quality and soil nutrients were investigated in a kiwifruit orchard after long-term fertilization to understand the relationship between kiwifruit growth and soil nutrition.Seven fertilization treatments with three replications were applied in a continuous four-year period,including no fertilizer(CK);phosphorus(P)and potassium(K)fertilizers(PK);N and K fertilizers(NK);N and P fertilizers(NP);N,P and K fertilizers(NPK);1.5 times of N,P and K fertilizers(1.5NPK);and chemical fertilizers plus swine manure(NPKM).Fertilization increased kiwifruit yield at the rate of 450 kg N/hm^(2),225 kg P2O5/hm^(2),300 kg K2O/hm^(2).The average yield decreased in a descending order for NPKM(44.6 t/hm^(2)),1.5NPK(42.6 t/hm^(2)),NPK(42.0 t/hm^(2)),NK(38.0 t/hm^(2)),NP(36.7 t/hm^(2)),PK(36.4 t/hm^(2))and CK(34.1 t/hm^(2)).The sugar to acid ratio(S:A)was the highest(10.9)in 2012,and the soluble sugar increased by 15.7%after four-year NPKM fertilization.The NPKM fertilization also significantly increased the vitamin C,soluble solid and firmness.The soil organic carbon contents at 0-20 cm,20-40 cm and 40-60 cm in depth under the NPKM treatment were 27%,29%and 139%higher than that of the CK treatment,respectively.The available N contents at 0-20 cm,20-40 cm and 40-60 cm in depth in the 1.5NPK treatment were 180%,114%and 133%higher than that in the CK treatment,respectively.Balanced fertilization with N,P,K and organic manure is important to soil fertility,which may increase yield and improve quality in field-grown kiwifruit orchard.
基金NIH/NICHD R01-HD075560the Carolina Population Center and its NIH/NICHD center grant(P2C HD050924)for general support.
文摘We focus on a small but growing segment of the U.S.population,those who identify as Chinese,Japanese and Korean(CJK),and compare CJK fertility to other race/ethnic groups in the United States.CJK women in the U.S.exhibit a distinct,pervasive,and persistent pattern of late and low fertility with nearly all births occurring within marriage;this pattern displays a strong parallel to their counterparts in their countries of origin.To accompany this description,we offer a perspective on fertility difference that has broad applicability and that does not consistently predict that differences will disappear/remain.This discussion unites the literature on assimilation,segmented assimilation and pluralistic outcomes and processes.We also discuss the possible implications of these findings for country level policies to increase fertility.Most generally,these discussions are a corrective to demographer’s penchant for predicting secular change and convergence.