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Zhao H.,Southwest University | Zhao H.,Guizhou Institute of Soil and Fertilizer | Li H.H.,Chongqing University of Arts and Sciences | Lu H.F.,Southwest University | Wang Z.Y.,Southwest University
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2013

The status of plant nutrient characteristic plays a vital role in yields. Therefore, 30 tumorous stem mustard farmers in Fuling district, Chongqing City, China, were selected in our present study, the variation characteristics of 10 necessary nutrients contents in leaves and stems of tumorous stem mustard in different growth stage (such as seedling, rapid expanding and harvest stage) were determined and also their relationship to the yields was set up by field survey and laboratory analysis. The results indicated that the contents of potassium (K) and sulfur (S) were both high during the whole growth periods. However, the other macroelements and microelements contents were fit to the normal plants; and also, the changes of nutrient content in leaves and stems were varied by the different growth stages, in generally, the contents in leaves at seeding stage was in the orders of nitrogen (N) >potassium (K) >calcium (Ca) >phosphate (P) > sulfur (S) >magnesium (Mg); macroelements content in the leaves at rapid expanding stage and harvest time were in the seriers of N>K>Ca>S>P >Mg. While in stems were followed by the order: K >N >P >S >Ca >Mg; Except rapid expanding stage(ferrum (Fe) >zinc (Zn) > manganese (Mg) >copper (Cu)), leaves and stems in all three growth periods were in the order of Fe >Mn >Zn >Cu. The contents of N, P, K, Fe, Cu and Zn in the leaves decreased from seedling stage to harvest time, while the contents of Ca, Mg, S and Mn decreased firstly, and then increased from seedling stage to harvest time,. From rapid expanding stage to harvest time, the contents of N, S, Fe and Cu showed a decreasing tendency, while other elements were the increasing tendency. In addition, the nutrient contents in different organs were also observed, the contents of N, P, K, Cu and Zn in leaves at rapid expanding stage and harvest time were lower than that of the stem nodule. But the contents of Ca, Fe and Mn showed the adverse pattern. S and Mg contents varied little, which indicated that the sensitivity of different parts of tumorous stem mustard to different nutrients were different. Correlation analysis showed that there were significant negative relationship between Mg, Fe, Mn, Zn in various organs at different growth stages and yields, however, K, Cu had the positive correlation with yields. Stepwise regression analysis was chosen to establish a predictive regression model between nutritive elements among different growth stages of tumorous stem mustard and yields, the optimum regression equation was obtained as follows, Y = 36768 + 3583XK-6.328XFe-76.09XMn at seedling stage, Y = 50458+21557XP +7925XCa-88092XMg-1145XCu and Y = 32487 + 7294XK-116122XMg for nutritive elements in leaves and stems at expanded quickly stage, respectively. while Y = 36064 + 3413XK-30. 15XFe and Y = 11791 + 7334XK-385XZn in harvesting time. It can concluded that more attention should be paid to the rational application of K fertilizer in every growth stage of tumorous stem mustard, and P fertilizer in rapid expanding stage. The negative effects of some trace elements and Mg on yield of tumorous stem mustard could be regulated by increasing the application of organic manure compost. Source

Shen P.,Chinese Academy of Agricultural Sciences | He X.-H.,Chinese Academy of Agricultural Sciences | He X.-H.,University of Western Australia | Xu M.-G.,Chinese Academy of Agricultural Sciences | And 7 more authors.
Journal of Integrative Agriculture | Year: 2014

Soil organic carbon (SOC) and soil Olsen-P are key soil fertility indexes but information on their relationships is limited particularly under long-term fertilization. We investigated the relationships between SOC and the percentage of soil Olsen-P to total P (PSOPTP) under six different 15-yr (1990-2004) long-term fertilizations at two cropping systems in northern China. These fertilization treatments were (1) unfertilized control (control); (2) chemical nitrogen (N); (3) N plus chemical P (NP); (4) NP plus chemical potassium (NPK); (5) NPK plus animal manure (NPKM) and (6) high NPKM (hNPKM). Compared with their initial values in 1989 at both sites, during the 11th to 15th fertilization years annual mean SOC contents were significantly increased by 39.4-47.0% and 58.9-93.9% at Gongzhuling, Jilin Province, and Urumqi, Xinjiang, China, under the two NPKM fertilizations, respectively, while no significant changes under the no-P or chemical P fertilization. During the 11th to 15th fertilization years, annual mean PSOPTP was respectively increased by 2.6-4.2 and 5.8-14.1 times over the initial values under the two chemical P fertilizations and the two NPKM fertilizations, but was unchanged in their initial levels under the two no-P fertilizations at both sites. Over the 15-yr long-term fertilization SOC significantly positively correlated with PSOPTP (r2=0.55-0.79, P<0.01). We concluded that the combination of chemical P plus manure is an effective way to promote SOC accumulation and the percentage of soil Olsen-P to total P at the two mono-cropping system sites in northern China. © 2014 Chinese Academy of Agricultural Sciences. Source

Zhao H.,Southwest University | Zhao H.,Guizhou Institute of Soil and Fertilizer | Qin S.,Guizhou Institute of Soil and Fertilizer | Wang Z.-Y.,Southwest University | And 2 more authors.
Chinese Journal of Applied Ecology | Year: 2013

By combining field investigation and indoor chemical analysis, the relationship between tumorous stem mustard yield and soil fertility factors was investigated in the main planting areas of tumorous stem mustard in Fuling, Southwest China. The results showed that available Ca, Mg, Fe, Mn, Cu and Zn in the soil were rich (3034, 260, 11.2, 26.1, 1.15 and 1.50 mg·kg-1, respectively), available P was moderate (19.3 mg·kg-1), and organic matter, available N, available K and available S were deficient (9.05 g · kg-1, 89.2 mg · kg-1, 106 mg · kg-1 and 27.0 mg·kg-1, respectively). The yield of tumorous stem mustard was significantly positively correlated with soil pH and available Ca, whilst significantly (P<0.01) negatively correlated with available Fe. The influence order of soil fertility factors on the yield of tumorous stem mustard was available Mn > available Cu > pH > available Fe > available K > available Ca > available Mg > available S > available N > available Zn > organic matter > available P. The linear equation (Y=31636+3.63X6) of soil available Ca and the yield, was established by stepwise regression analysis. Source

Dai Z.,Chinese Academy of science | Dai Z.,University of Chinese Academy of Sciences | Feng X.,Chinese Academy of science | Zhang C.,Chinese Academy of science | And 9 more authors.
Environmental Science and Pollution Research | Year: 2013

Long-term mining and smelting activities brought a series of environmental issues into soils in Wanshan mercury (Hg) mining area (WMMA), Guizhou, China. Several studies have been published on the concentrations of Hg in local soils, but a comprehensive assessment of the mass of Hg in soil induced by anthropogenic activities, as presented in this paper, has not been previously conducted. Three districts of WMMA were chosen as the study areas. We summarized previous published data and sampled 14 typical soil profiles to analyze the spatial and vertical distributions of Hg in soil in the study areas. The regional geologic background, direct and indirect Hg deposition, and Hg-polluted irrigation water were considered as the main sources of Hg contaminations in local soils. Furthermore, the enrichment factor (EF) method was applied to assess the extent of anthropogenic input of Hg to soil. Titanium (Ti) was chosen to be the reference element to calculate the EF. Generally, the elevated values of EF were observed in the upper soil layers and close to mine wastes. The total budget of Hg in soil contributed from anthropogenic sources was estimated to be 1,227 t in arable soil and 75 t in natural soil. Our data showed that arable soil was the major sink of anthropogenic Hg in the study area. © 2013 Springer-Verlag Berlin Heidelberg. Source

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