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1.
Effect of root contact on interspecific competition and N transfer between wheat and fababean using direct and indirect 15N techniques 总被引:7,自引:0,他引:7
Plant and Soil - Pot experiments were carried out to investigate the complementary N use between intercropped fababean (Vicia faba L. cv. Linxia Dacandou) and wheat (Triticum aestivum L cv. 8354).... 相似文献
2.
Mingsheng Fan Xuejun Liu Rongfeng Jiang Fusuo Zhang Shihua Lu Xiangzhong Zeng Peter Christie 《Plant and Soil》2005,277(1-2):265-276
A field experiment was conducted for 5 years to examine the effects of non-flooded mulching cultivation on crop yield, internal
nutrient efficiency and soil properties in rice–wheat (R–W) rotations of the Chengdu Plain, southwest China. Compared with
traditional flooding (TF), non-flooded plastic film mulching (PM) resulted in 12 and 11% higher average rice (Oryza sativa L.) yield and system productivity (combined rice and wheat yields), and the trends in rice and wheat (Triticum aestivum L.) yields under PM were stable over time. However, non-flooded wheat straw mulching (SM) decreased average rice yield by
11% compared with TF, although no significant difference in system productivity was found between SM and TF. Uptakes of N
and K by rice under PM were higher than those under TF and SM, but internal nutrient efficiency was significantly lower (N)
or similar (K) under PM compared to SM and TF. This implies that more N and K accumulated in rice straw under PM. After 5-year
rice–wheat rotation, apparent P balances (112–160 kg ha−1) were positive under all three cultivation systems. However, the K balances were negative under PM (−419 kg ha−1) and TF (−90 kg ha−1) compared with SM (45 kg ha−1). This suggests that higher K inputs from fertilizer, straw or manure may be necessary, especially under PM. After five rice
seasons and four wheat seasons, non-flooded mulching cultivation led to similar (PM) or higher (SM) soil organic carbon (SOC),
total N (TN) and alkali hydrolyzable N (AH-N) in the top 0–5 and 5–12 cm layers compared with TF. SOC, TN, AH-N and Olsen-P
(OP) in the sub-surface layer (12–24 cm) were significantly higher under PM or SM than under TF, indicating that rice under
non-flooded mulching conditions may fail to make use of nutrients from the subsoil. Thus, the risk of decline in soil fertility
under non-flooded mulching cultivation could be very low if input levels match crop requirements. Our data indicate that PM
and SM may be alternative options for farmers using R–W rotations for enhancement or maintenance of system productivity and
soil fertility. 相似文献
3.
We examined cluster root formation and root exudation by white lupin (Lupinus albus L. cv. Kiev Mutant) in response to growth medium and phosphorus supply in a sand/solution split-root system. The split-root
system consisted of a nutrient solution compartment and a siliceous sand compartment. Phosphorus was applied at 1 (low-P plants)
or 50 (high-P plants) μM as KH2PO4 to the solution compartment and at 10, 50 or 250 mg P kg−1 as hydroxyapatite (Ca-P) to the sand compartment. In contrast to the high-P plants, P concentration and P uptake in the low-P
plants increased with increasing P supply to the sand compartment. The NaHCO3-extractable P was lower in the rhizosphere of the low-P plants than the high-P ones. The proton extrusion rate by the solution-grown
roots of the low-P plants was higher than that of the high-P plants at the early growth stage. For the low-P plants, the proportion
of dry root biomass allocated to cluster roots was higher in the solution compartment than that in the sand compartment. The
citrate exudation increased in the sand compartment and decreased in the solution compartment with time, showing a lack of
synchronization in citrate exudation by two root halves grown in different media. The cluster root proportion and citrate
exudation in both compartments decreased with increasing shoot P concentration. An additional experiment with no P added to
either root compartment showed that the proportion of cluster roots was about 9% lower in the sand than solution compartments.
The results suggest that cluster root formation and citrate exudation can be significantly affected by the root growth medium
in addition to being regulated by shoot P status. More P can be exploited from sparingly available Ca-P by the low-P plants
than the high-P ones due to greater citrate exudation under P deficiency. 相似文献
4.
The critical soil P levels for crop yield, soil fertility and environmental safety in different soil types 总被引:34,自引:0,他引:34
Zhaohai Bai Haigang Li Xueyun Yang Baoku Zhou Xiaojun Shi Boren Wang Dongchu Li Jianbo Shen Qing Chen Wei Qin Oene Oenema Fusuo Zhang 《Plant and Soil》2013,372(1-2):27-37
Background and aims
Sufficient soil phosphorus (P) is important for achieving optimal crop production, but excessive soil P levels may create a risk of P losses and associated eutrophication of surface waters. The aim of this study was to determine critical soil P levels for achieving optimal crop yields and minimal P losses in common soil types and dominant cropping systems in China.Methods
Four long-term experiment sites were selected in China. The critical level of soil Olsen-P for crop yield was determined using the linear-plateau model. The relationships between the soil total P, Olsen-P and CaCl2-P were evaluated using two-segment linear model to determine the soil P fertility rate and leaching change-point.Results
The critical levels of soil Olsen-P for optimal crop yield ranged from 10.9 mg kg?1 to 21.4 mg kg?1, above which crop yield response less to the increasing of soil Olsen-P. The P leaching change-points of Olsen-P ranged from 39.9 mg kg?1 to 90.2 mg kg?1, above which soil CaCl2-P greatly increasing with increasing soil Olsen-P. Similar change-point was found between soil total P and Olsen-P. Overall, the change-point ranged from 4.6 mg kg?1 to 71.8 mg kg?1 among all the four sites. These change-points were highly affected by crop specie, soil type, pH and soil organic matter content.Conclusions
The three response curves could be used to access the soil Olsen-P status for crop yield, soil P fertility rate and soil P leaching risk for a sustainable soil P management in field. 相似文献5.
Qingfeng Meng Shanchao Yue Xinping Chen Zhenling Cui Youliang Ye Wenqi Ma Yanan Tong Fusuo Zhang 《PloS one》2013,8(7)
Understanding the time-course of dry matter (DM) and nitrogen (N) accumulation in terms of yield–trait relationships is essential to simultaneously increase grain yield and synchronize N demand and N supply. We collected 413 data points from 11 field experiments to address patterns of DM and N accumulation with time in relation to grain yield and management of winter wheat in China. Detailed growth analysis was conducted at the Zadok growth stages (GS) 25 (regreening), GS30 (stem elongation), GS60 (anthesis), and GS100 (maturity) in all experiments, including DM and N accumulation. Grain yield averaged 7.3 Mg ha−1, ranging from 2.1 to 11.2 Mg ha−1. The percent N accumulation was consistent prior to DM accumulation, while both DM and N accumulation increased continuously with growing time. Both the highest and fastest DM and N accumulations were observed from stem elongation to the anthesis stage. Significant correlations between grain yield and DM and N accumulation were found at each of the four growth stages, although no positive relationship was observed between grain yield and harvest index or N harvest index. The yield increase from 7–9 Mg ha−1 to >9 Mg ha−1 was mainly attributed to increased DM and N accumulation from stem elongation to anthesis. Although applying more N fertilizer increased N accumulation during this stage, DM accumulation was not improved, indicating that N fertilizer management and related agronomic management should be intensified synchronously across the wheat growing season to simultaneously achieve high yields and match N demand and N supply. 相似文献
6.
Abstract Being a new cultivar, the physiology of transgenic cotton, especially dual-toxin transgenic (Bt+CpTI) cotton, is not yet completely understood. Twelve elements in three organs of dual-toxin transgenic cotton seedlings were analyzed by ICP-MS. The distributions of the 12 elements were substantially different from those of non-transgenic cotton. In particular, the contents of B, Mg, P, K and Ca were the highest in leaves, while those of Si, Fe, Rb and Cu were the highest in roots; other elements had similar contents in the two organs, which were higher than those in the stem. Compared with non-transgenic cotton, the 12 elements could be classified into four groups according to their contents and distributions in the three organs: (a) P, K and Cu: their contents in transgenic cotton were remarkably lower, especially contents of P and K in leaves that were one times lower than those in leaves of non-transgenic cotton; (b) B, Mg and Mo: their contents in leaves and roots of transgenic cotton were higher, but lower in stems, compared with non-transgenic cotton; (c) Si, Mn, Fe, Rb and Zn: compared with non-transgenic cotton, these were lower in leaves and stems, but higher in roots of transgenic cotton; and (d) Ca: compared with non-transgenic cotton, its content was higher in all three organs of the transgenic counterpart. The decrease in soluble proteins and the expression of Bt and CpTI genes could be responsible for these changes. Further studies are needed to verify this hypothesis. 相似文献
7.
Modern maize hybrids in Northeast China exhibit increased yield potential and resource use efficiency despite adverse climate change 总被引:10,自引:0,他引:10
Xiaochao Chen Fanjun Chen Yanling Chen Qiang Gao Xiaoli Yang Lixing Yuan Fusuo Zhang Guohua Mi 《Global Change Biology》2013,19(3):923-936
The impact of global changes on food security is of serious concern. Breeding novel crop cultivars adaptable to climate change is one potential solution, but this approach requires an understanding of complex adaptive traits for climate‐change conditions. In this study, plant growth, nitrogen (N) uptake, and yield in relation to climatic resource use efficiency of nine representative maize cultivars released between 1973 and 2000 in China were investigated in a 2‐year field experiment under three N applications. The Hybrid‐Maize model was used to simulate maize yield potential in the period from 1973 to 2011. During the past four decades, the total thermal time (growing degree days) increased whereas the total precipitation and sunshine hours decreased. This climate change led to a reduction of maize potential yield by an average of 12.9% across different hybrids. However, the potential yield of individual hybrids increased by 118.5 kg ha?1 yr?1 with increasing year of release. From 1973 to 2000, the use efficiency of sunshine hours, thermal time, and precipitation resources increased by 37%, 40%, and 41%, respectively. The late developed hybrids showed less reduction in yield potential in current climate conditions than old cultivars, indicating some adaptation to new conditions. Since the mid‐1990s, however, the yield impact of climate change exhibited little change, and even a slight worsening for new cultivars. Modern breeding increased ear fertility and grain‐filling rate, and delayed leaf senescence without modification in net photosynthetic rate. The trade‐off associated with delayed leaf senescence was decreased grain N concentration rather than increased plant N uptake, therefore N agronomic efficiency increased simultaneously. It is concluded that modern maize hybrids tolerate the climatic changes mainly by constitutively optimizing plant productivity. Maize breeding programs in the future should pay more attention to cope with the limiting climate factors specifically. 相似文献
8.
Guangzhou Wang Peggy Schultz Alice Tipton Junling Zhang Fusuo Zhang James D. Bever 《Ecology letters》2019,22(8):1221-1232
Which processes drive the productivity benefits of biodiversity remain a critical, but unanswered question in ecology. We tested whether the soil microbiome mediates the diversity‐productivity relationships among late successional plant species. We found that productivity increased with plant richness in diverse soil communities, but not with low‐diversity mixtures of arbuscular mycorrhizal fungi or in pasteurised soils. Diversity‐interaction modelling revealed that pairwise interactions among species best explained the positive diversity‐productivity relationships, and that transgressive overyielding resulting from positive complementarity was only observed with the late successional soil microbiome, which was both the most diverse and exhibited the strongest community differentiation among plant species. We found evidence that both dilution/suppression from host‐specific pathogens and microbiome‐mediated resource partitioning contributed to positive diversity‐productivity relationships and overyielding. Our results suggest that re‐establishment of a diverse, late successional soil microbiome may be critical to the restoration of the functional benefits of plant diversity following anthropogenic disturbance. 相似文献
9.
From Flooded to Aerobic Conditions in Rice Cultivation: Consequences for Zinc Uptake 总被引:1,自引:1,他引:0
Scarcity of water causes a shift from flooded to aerobic conditions for rice production in zinc deficient areas in Northern
China. This shift alters soil conditions that affect zinc availability to the crop. This paper concerns the effect of aerobic
compared to flooded conditions on crop biomass production, grain yield and zinc content. A field experiment was done with
six rice genotypes (Oryza sativa L.) grown on a calcareous soil, both with (23 kg Zn ha−1) and without Zn fertilization. Sampling was conducted at tillering and physiological mature stage. Zn concentration in the
shoots was significantly lower at both stages in plants grown in the aerobic field. At maturity, Zn uptake, biomass production,
grain yield and Zn-harvest index [grain Zn/(shoot + grain Zn)] were lower under aerobic cultivation. Rice genotypes including
aerobic rice and lowland rice differ in degree of response to low Zn supply. A twofold difference was found among aerobic
genotypes in grain yield and Zn uptake. Also Zn-harvest index varied significantly. Zn application affected neither grain
yield nor grain Zn content, although it significantly improved biomass production in both systems in most genotypes. These
results demonstrate that introduction of aerobic rice systems on calcareous soils may increase Zn deficiency problems. 相似文献
10.
Spatial and temporal variation of atmospheric nitrogen deposition in the North China Plain 下载免费PDF全文
A monitoring network of nine sites was established to determine the spatial and temporal variation of atmospheric nitrogen (N) deposition in the North China Plain (NCP) over a two-year period. The annual bulk deposition of inorganic N in the North China Plain ranged from 18.4 to 38.5 kg/hm2 and averaged 28.0 kg/hm2. The concentration of NH4 -N and NO3--N in rainwater averaged 3.76 and 1.85 mg/L, respectively, which were significantly higher than the values at background sites in China (normally less than 0.5 mg/L). Annual bulk deposition of inorganic N in the Beijing area (32.5 kg/hm2) was higher than that in Shandong and Hebei provinces (21.2 kg/hm2 on an average). Also bulk N deposition was much greater in Dongbeiwang and Fangshan than in Yanqing and Shunyi counties. Significant spatial variation of bulk deposition was observed in the Beijing area because of variation of precipitation, and 60% of bulk deposition occurred from June to September. Bulk deposition of NH4 -N was 2.0 times that of NO3--N deposition at the rural monitoring sites. However, the situation was reversed at the Beijing Academy of Agricultural-Forestry Sciences (BAAFS), the unique urban monitoring site. The results suggest that reduced N in precipitation is dominant in rural regions, but oxidized N is the major form in urban regions. The positive relationship between inorganic N deposition and precipitation can be fitted by a power equation (r2= 0.67), showing an increase of NH4 -N and NO3--N inputs with increased precipitation. Wet deposition of N accounted for 73% of the bulk deposition, implying that dry deposition of N, particularly NH4 -N from dust, is important in the North China Plain. 相似文献