Biochar effects on crop yields with and without fertilizer: A meta‐analysis of field studies using separate controls

2019 ◽  
Vol 36 (1) ◽  
pp. 2-18 ◽  
Author(s):  
Lili Ye ◽  
Marta Camps‐Arbestain ◽  
Qinhua Shen ◽  
Johannes Lehmann ◽  
Balwant Singh ◽  
...  
Keyword(s):  
Crop Yields ◽  
Meta Analysis ◽  
Field Studies

scholarly journals Outcomes of Long-Term Conservation Tillage Research in Northern China

2020 ◽  
Vol 12 (3) ◽  
pp. 1062 ◽  
Author(s):  
Francis Azumah Chimsah ◽  
Liqun Cai ◽  
Jun Wu ◽  
Renzhi Zhang
Keyword(s):  
Crop Yields ◽  
Greenhouse Gas Emission ◽  
Conservation Tillage ◽  
Cropping Systems ◽  
Meta Analysis ◽  
Arable Land ◽  
Aggregate Stability ◽  
Northern China ◽  
Total N

Sustainable food production has long been a priority for mankind and this is being challenged by limited arable land, challenged landscapes, and higher human population growth. China started conservation farming around the 1950’s. However, main Conservation Tillage (CT) research started in 1992. Using a systematic meta-analysis approach, this review aims at examining China’s approach to CT and to characterize the main outcomes of long-term CT research across northern China. Data from organizations in charge of CT research in China showed an improvement in crop yield of at least 4% under double cropping systems and 6% under single cropping systems in dry areas of northern China. Furthermore, long-term CT practices were reported to have improved soil physical properties (soil structure, bulk density, pore size, and aggregate stability), soil nutrient levels, and reduction in greenhouse gas emission. Other benefits include significant increase in income levels and protection of the environment. Limitations to CT practice highlighted in this study include occasional reduction in crop yields during initial years of cropping, significant reduction in total N of soils, increase in N2O emission, and the need for customized machinery for its implementation. Outcomes of CT practice are ecologically and economically beneficial though its limitations are worth cogitating.

scholarly journals Replacing Synthetic Nitrogen Fertilizer with Different Types of Organic Materials Improves Grain Yield in China: A Meta-Analysis

Agronomy ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2429
Author(s):  
Xiaoru Fan ◽  
Zekai Chen ◽  
Zihan Niu ◽  
Ruiyao Zeng ◽  
Jingmin Ou ◽  
...  
Keyword(s):  
Grain Yield ◽  
Nitrogen Fertilizer ◽  
Organic Materials ◽  
Crop Yields ◽  
Meta Analysis ◽  
Chicken Manure ◽  
Agricultural Practice ◽  
Different Types ◽  
Synthetic Nitrogen Fertilizer

Synthetic nitrogen fertilizer substitution (NSS) with different types of organic material is a cleaner agricultural practice for reducing the application of synthetic N input in farmlands while also relieving the environmental issues caused by the discharge of organic wastes. However, the effects of the NSS practice on crop yields, being the primary objective of agricultural activity, is still uncertain in China. This study conducted a meta-analysis to assess the impacts of the NSS practices with different types of organic materials on crop yields. Results showed that the average crop yield was increased by 3.4%, with significant differences under NSS, thereby demonstrating that this practice contributed to improving crop yields, especially of rice and maize. According to published reports, the NSS practices involving chicken manure, pig manure, and crop straw increased crop yields by 4.79, 7.68, and 3.28%, respectively, with significant differences, thus demonstrating the superior effects needed for replacing synthetic N fertilizer. Moreover, substitution ratios (SR) between 0% and 60% could be suggested when using the NSS practice, with the high SR recommended when the original soil fertility was adequate for crops. Considering the long-term effects of applied organic materials, improving the grain yield with the NSS practice should be expected in the long-term. By effectively applying the NSS, this study attempted to scientifically decide on the type of organic materials and the appropriate SR based on the conditions of the soil and the crop. The results provide research information for the development of clean agricultural production and food security in China.

scholarly journals PRODUCTIVITY OF PERENNIAL GRASSES AND MIXTURES WITH DIFFERENT SOWING DATES IN WESTERN SIBERIA

2020 ◽  
pp. 24-32
Author(s):  
V. A. Petruk
Keyword(s):  
Dry Matter ◽  
Crop Yields ◽  
Growing Season ◽  
Single Species ◽  
Field Studies ◽  
Perennial Grasses ◽  
First Year ◽  
Sowing Dates ◽  
Second Year ◽  
Sowing Period

The results of field studies for 2017 - 2019 are presented. yields of perennial grasses sown at different times of the growing season. Spring, summer, and winter sowing periods were compared. Alfalfa, clover, rump, and also their mixtures were sown in 2017 under the cover of barley. The value of the cover crop yield of spring and summer sowing periods did not differ significantly and amounted to 4-5 t / ha of absolutely dry matter. Winter barley crops have not formed. On average, over 2 years of use, the highest yields were observed in alfalfa-crust grass mixtures - 3.4 t / ha of absolutely dry matter. The lowest yield was obtained in the single-species seeding of the rump. Correspondingly, in the spring, summer and winter periods of sowing, the yield of rump was 1.6; 1.1 and 1.3 t / ha. With a late sowing period, the yield of perennial grasses is significantly lower compared to spring and summer. With winter sowing periods, the yield was the highest for grass stands of alfalfa and alfalfacrust grass mixture - 2.3 and 2.4 t / ha. It should be noted that in the second year of use, the yield by the sowing dates in single-species crops and grass mixtures is leveled. The winter crops of perennial grasses in the first year of use formed a low yield. Only in the second year (third year of life) the productivity of perennial grasses of winter sowing began to increase. Consequently, in the area under perennial grasses of the winter sowing period, during one growing season (the next year after sowing), the crop was not actually formed. Based on the data obtained, production can be recommended for spring and summer planting of perennial grasses under the cover of barley. The winter sowing period provides economically valuable crop yields only by the third year of life.

scholarly journals Organic Farming Provides Reliable Environmental Benefits but Increases Variability in Crop Yields: A Global Meta-Analysis

2019 ◽  
Vol 3 ◽  
Author(s):  
Olivia M. Smith ◽  
Abigail L. Cohen ◽  
Cassandra J. Rieser ◽  
Alexandra G. Davis ◽  
Joseph M. Taylor ◽  
...  
Keyword(s):  
Organic Farming ◽  
Crop Yields ◽  
Meta Analysis ◽  
Environmental Benefits

scholarly journals The association between depression and later educational attainment in children and adolescents: a systematic review protocol

BMJ Open ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. e031595 ◽  
Author(s):  
Alice Wickersham ◽  
Sophie Epstein ◽  
Holly Victoria Rose Sugg ◽  
Robert Stewart ◽  
Tamsin Ford ◽  
...  
Keyword(s):  
Educational Attainment ◽  
Children And Adolescents ◽  
Data Extraction ◽  
Meta Analysis ◽  
Field Studies ◽  
Health Concern ◽  
Published Data ◽  
Eligibility Criteria ◽  
Newcastle Ottawa Scale ◽  
Date Estimate

IntroductionDepression represents a major public health concern for children and adolescents, and is thought to negatively impact subsequent educational attainment. However, the extent to which depression and educational attainment are directly associated, and whether other factors play a role, is uncertain. Therefore, we aim to systematically review the literature to provide an up-to-date estimate on the strength of this association, and to summarise potential mediators and moderators on the pathway between the two.Methods and analysisTo identify relevant studies, we will systematically search Embase, PsycINFO, PubMed, Education Resources Information Centre and British Education Index, manually search reference lists and contact experts in the field. Studies will be included if they investigate and report on the association between major depression diagnosis or depressive symptoms in children and adolescents aged 4–18 years (exposure) and later educational attainment (outcome). Two independent reviewers will screen titles, abstracts and full texts according to eligibility criteria, perform data extraction and assess study quality according to a modified version of the Newcastle-Ottawa Scale. If sufficiently homogeneous studies are identified, summary effect estimates will be pooled in meta-analysis, with further tests for study heterogeneity, publication bias and the effects of moderators using meta-regression.Ethics and disseminationBecause this review will make use of already published data, ethical approval will not be sought. The review will be submitted for publication in a peer-reviewed journal, presented at practitioner-facing conferences, and a lay summary will be written for non-scientific audiences such as parents, young people and teachers. The work will inform upcoming investigations on the association between child and adolescent mental health and educational attainment.PROSPERO registration numberCRD42019123068

Meta-analysis of crop yields of full, deficit, and partial root-zone drying irrigation

2018 ◽  
Vol 197 ◽  
pp. 79-90 ◽  
Author(s):  
Michael O. Adu ◽  
David O. Yawson ◽  
Frederick A. Armah ◽  
Paul A. Asare ◽  
Kwame A. Frimpong
Keyword(s):  
Crop Yields ◽  
Root Zone ◽  
Meta Analysis
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