•Water retention agent can improve soil water condition in maize cultivation.•Advantage of controlled-release urea was higher with deep application.•Positive interaction of conventional urea and ...water retention agent was observed.•Application of controlled-release urea without water retention agent is more effective.
Controlled-release urea has been widely adopted to increase nitrogen (N) use efficiency and crop production, and these effects can range widely depending on water availability in soil. However, limited information is available on the interaction of controlled-release urea placement depth with water retention agent (WRA) on N and water use and the yield of crops. The objectives of this study were to assess the consequences of this interaction on N and water use and the maize (Zea mays L.) yield by a split-plot design with WRA as the main plots and five application methods of urea as sub-plots. The five application methods consisted of inter-row side dressing of conventional urea at 5cm and 10cm depths, inter-row side dressing of controlled-release urea at 5cm and 10cm depths, and deep placement of the controlled-release urea at a 15cm depth. Soil water stocks, dry matter accumulation, 1000-grain weight, grain-filling rate, N and water use efficiencies, and economic benefits were evaluated. The results revealed that the year, WRA, urea, and their interactions had significant effects on N and water use efficiencies, yield and benefits. When controlled-release urea was placed deep, soil water stocks were higher from the male tetrad stage to maturity and evapotranspiration (ETα) increased. Deep placement of controlled-release urea at a 15cm depth without WRA enhanced the agronomic efficiency of N and water. The yield and net income were increased compared with controlled-release urea at a 5cm depth. The combination of WRA and deep placement of controlled-release urea at a 15cm depth had a significant effect on water use efficiency. However, this combination had no significant effects on N use efficiency, yield and benefits. WRA used with conventional urea can maintain higher soil water stocks, and increase the dry matter production, grain-filling rate, N and water use efficiencies. The differences were more significant during the dry season. Conventional urea at a 10cm depth with WRA enhanced N and water use efficiencies, yield and net income by 6.5, 3.2, 6.5 and 4.2% respectively when compared with conventional urea without WRA. Thus, the best solution to obtain higher yield, water and N use efficiencies, and net income is placing controlled-release urea at 15-cm depth without WRA. When controlled-release urea is not available, placing conventional urea at a 10-cm depth combined with WRA is an interesting alternative for farmers.
Protein lysine acetylation (Kac) is an important post-translational modification in both animal and plant cells. Global Kac identification has been performed at the proteomic level in various ...species. However, the study of Kac in oil and resource plant species is relatively limited. Soybean is a globally important oil crop and resouce plant. In the present study, lysine acetylome analysis was performed in soybean leaves with proteomics techniques. Various bioinformatics analyses were performed to illustrate the structure and function of these Kac sites and proteins. Totally, 3148 acetylation sites in 1538 proteins were detected. Motif analysis of these Kac modified peptides extracted 17 conserved motifs. These Kac modified protein showed a wide subcellular location and functional distribution. Chloroplast is the primary subcellular location and cellular component where Kac proteins were localized. Function and pathways analyses indicated a plenty of biological processes and metabolism pathways potentially be influenced by Kac modification. Ribosome activity and protein biosynthesis, carbohydrate and energy metabolism, photosynthesis and fatty acid metabolism may be regulated by Kac modification in soybean leaves. Our study suggests Kac plays an important role in soybean physiology and biology, which is an available resource and reference of Kac function and structure characterization in oil crop and resource plant, as well as in plant kingdom.
Key message
Coincident regions on chromosome 4B for GW, on 5A for SD and TSS, and on 3A for SL and GNS were detected through an integration of a linkage analysis and a genome-wide association study ...(GWAS). In addition, six stable QTL clusters on chromosomes 2D, 3A, 4B, 5A and 6A were identified with high PVE% on a composite map.
The panicle traits of wheat, such as grain number per spike and 1000-grain weight, are closely correlated with grain yield. Superior and effective alleles at loci related to panicles developments play a crucial role in the progress of molecular improvement in wheat yield breeding. Here, we revealed several notable allelic variations of seven panicle-related traits through an integration of genome-wide association mapping and a linkage analysis. The linkage analysis was performed using a recombinant inbred line (RIL) population (173 lines of F
8:9
) with a high-density genetic map constructed with 90K SNP arrays, Diversity Arrays Technology (DArT) and simple sequence repeat (SSR) markers in five environments. Thirty-five additive quantitative trait loci (QTL) were discovered, including eleven stable QTLs on chromosomes 1A, 2D, 4B, 5B, 6B, and 6D. The marker interval between
EX_C101685
and
RAC875_C27536
on chromosome 4B exhibited pleiotropic effects for GW, SL, GNS, FSN, SSN, and TSS, with the phenotypic variation explained (PVE) ranging from 5.40 to 37.70%. In addition, an association analysis was conducted using a diverse panel of 205 elite wheat lines with a composite map (24,355 SNPs) based on the Illumina Infinium assay in four environments. A total of 73 significant marker-trait associations (MTAs) were detected for panicle traits, which were distributed across all wheat chromosomes except for 4D, 5D, and 6D. Consensus regions between
RAC875_C27536_611
and
Tdurum_contig4974_355
on chromosome 4B for GW in multiple environments, between
QTSS5A.7
-
43
and
BS00021805_51
on 5A for SD and TSS, and between
QSD3A.2
-
164
and
RAC875_c17479_359
on 3A for SL and GNS in multiple environments were detected through linkage analysis and a genome-wide association study (GWAS). In addition, six stable QTL clusters on chromosomes 2D, 3A, 4B, 5A, and 6A were identified with high PVE% on a composite map. This study provides potentially valuable information on the dissection of yield-component traits and valuable genetic alleles for molecular-design breeding or functional gene exploration.
•Effects of 10 years conservation tillage plus 4 years deep tillage experiments were investigated in North China.•Crop yield and soil carbon were significant changed by conservation tillage ...conversion to deep tillage.•Deep tillage increased crop yields by 35, 24 and 24% compared with no tillage, rotary tillage and harrow tillage.•Deep tillage altered SOC pools by −1.5, 15.6 and 13.2Mgha−1 compared with no tillage, rotary tillage and harrow tillage.
Subsoil compaction at 15–30cm depths due to the increase of bulk density or decrease in porosity after long-term no tillage or reduced tillage (e.g. rotary tillage or harrow tillage) is of growing concern. Deep tillage is generally regarded as an important method to reduce subsoil compaction due to long-term conservation tillage and thereby improve crop production and soil conditions. We compared the responses of crop yield and soil carbon (C) among 10-year no tillage (NT), rotary tillage (RT), and harrow tillage (HT) treatments, and their conversions to deep tillage (DT) for 4 years involving NT-DT, RT-DT and HT-DT treatments. The soil organic carbon (SOC) pool under the NT treatment was 29 and 91% higher than the SOC pools of the HT and RT treatments, respectively, whereas the NT annual yield decreased by 0.6Mgha−1yr−1 over 10 years. The NT-DT, RT-DT and HT-DT treatments increased crop yield by 35, 24 and 24% and altered the SOC pool by −1.5, 15.6 and 13.2Mgha−1 over the 4 years of deep tillage compared with the corresponding values for NT, RT, and HT, respectively. Therefore, conversion to DT after long-term NT, RT, and HT use can benefit crop yield and play an important role in improving soil carbon sequestration following the long-term adoption of RT and HT systems in North China.
Long‐term tillage and straw incorporation significantly affect soil organic carbon (SOC) sequestration and crop yield. However, the studies on the SOC sources under multicropping system are ...relatively few. The objective of this study was to evaluate the effects of conservation tillage on SOC and crop yields and distinguish the SOC sources from wheat (C3) and maize (C4). Therefore, the dynamics of SOC, SOC sequestration, and crop yield were evaluated during 15 years of conservation agriculture under conventional tillage (CT), subsoiling (ST), rotary tillage (RT), and zero tillage (ZT) without or with straw incorporation (CTS, STS, RTS, and ZTS, respectively). The results indicated that the highest mean SOC concentration in the 0‐ to 30‐cm soil was found under STS (11.80 g kg−1), which increased by 2.29 g kg−1 than that under CT, whereas RT had the lowest mean SOC concentration (8.10 g kg−1). The increases in annual yield ranged from 0.58 (ZT) to 4.93 (ST) Mg ha−1 during 2005–2017. In comparison with the annual yield of CT, that of STS increased by 2 Mg ha−1 and was significantly higher than other treatments (p < .05) except ZTS and CTS. In comparison with CT, the SOC stock and carbon sequestration rate of STS were the highest and increased by 15.64 Mg ha−1 and 1.05 Mg ha−1 yr−1, respectively, in the 0‐ to 30‐cm soil. Moreover, the relative contribution of wheat residues to SOC was higher than maize residues under all treatments. Thus, subsoiling combined with C3 straw incorporation was more suitable for restoring degraded land and increasing yields.
With rising atmospheric carbon dioxide (CO
2
) concentrations globally, there is an urgent need for highly efficient CO
2
capture technologies. This report introduces an innovative technology to ...remove CO
2
of point sources using calcium hydroxide (Ca(OH)
2
) nanoparticles of 10 nm. Superior to regular CO
2
absorption methods, the nano-Ca(OH)
2
chemically increased reactive surface area and gas retention time of the scrubbing system. Experimental data show that CO
2
absorption capacity of the nano-suspension was over 8 times higher than that of the regular Ca(OH)
2
particles of 2 µm in size. In addition to CO
2
removal, nano-Ca(OH)
2
also has high potential to treating acidic gases such as HCl, SO
x
, or NO
x
, for improving air quality and offsetting the global warming trend. This is the first study on using Ca(OH)
2
nanoparticles for efficient CO
2
capture.
To assess changes in organic carbon pools, an incubation experiment was conducted under different temperatures and field moisture capacity (FMC) on a brown loam soil from three tillage practices used ...for 12 years: no‐till (NT), subsoiling (ST) and conventional tillage (CT). Total microbial respiration was measured for incubated soil with and without the input of straw. Results indicated that soil organic carbon (SOC) and microbial biomass carbon (MBC) under ST, NT and CT was higher in soil with straw input than that without, while the microbial quotient (MQ or MBC: SOC) and metabolic quotient (qCO2) content under CT followed the opposite trend. Lower temperature, lower moisture and with straw input contributed to the increases in SOC concentration, especially under NT and ST systems. The SOC concentrations under ST, with temperatures of 30 and 35°C after incubation at 55% FMC, were greater than those under CT by 28.4% and 30.6%, respectively. The increase in MBC was highest at 35°C for 55%, 65% and 75% FMC; in soil under ST, MBC was greater than that under CT by 199.3%, 50.7% and 23.8%, respectively. At 30°C, the lower qCO2 was obtained in soil incubated under NT and ST. The highest MQ among three tillage practices was measured under ST at 55% FMC, NT at 65% FMC and CT at 75% FMC with straw input. These data indicate the benefits of enhancing the MQ; the low FMC was beneficial to ST treatment. Under higher temperature and drought stress conditions, the adaptive capacity of ST and NT is better than that of CT.
Maize (
L.) is usually planted at high density, so most of its leaves grow in low light. Certain morphological and physiological traits improve leaf photosynthetic capacity under low light, but how ...light absorption, transmission, and transport respond at the proteomic level remains unclear. Here, we used tandem mass tag (TMT) quantitative proteomics to investigate maize photosynthesis-related proteins under low light due to dense planting, finding increased levels of proteins related to photosystem II (PSII), PSI, and cytochrome
. These increases likely promote intersystem electron transport and increased PSI end electron acceptor abundance. OJIP transient curves revealed increases in some fluorescence parameters under low light: quantum yield for electron transport (φE
), probability that an electron moves beyond the primary acceptor Q
(ψ
), efficiency/probability of electron transfer from intersystem electron carriers to reduction end electron acceptors at the PSI acceptor side (δR
), quantum yield for reduction of end electron acceptors at the PSI acceptor side (φR
), and overall performance up to the PSI end electron acceptors (PI
). Thus, densely planted maize shows elevated light utilization through increased electron transport efficiency, which promotes coordination between PSII and PSI, as reflected by higher apparent quantum efficiency (AQE), lower light compensation point (LCP), and lower dark respiration rate (R
).
Reducing CO
2
emissions from agricultural soils is a key component of the overall carbon reduction strategy. The closed chamber method was used to continuously monitor CO
2
concentration in soil ...profiles of winter wheat-summer maize rotation fields in the North China Plain (NCP) during 2015-2017. Additionally, we evaluated the contribution of different tillage methods (Rotary tillage (RT), Subsoiling (SS), No- tillage (ZT), and conventional tillage (CT) in combination with Straw return (s) and straw removal (0)) to reducing soil CO
2
emission. The results showed that the concentration of CO
2
increased with the soil depth and peaked at the 150 cm layer. The trend of CO
2
concentration in soil profiles under different tillage treatments was CT
S
> RT
S
> ZT
S
> SS
S
, and the average concentration in maize season was higher than that in wheat season. In addition, soil moisture and temperature in the 0-10 cm soil layer were significantly correlated with soil CO
2
concentrations. Thus, our results highlight that the SSs plays a critical role in moderating soil CO
2
emissions. This process merits further study to effectively regulate soil CO
2
release and achieve carbon neutrality with less carbon emissions in farmland ecosystems.
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