Turner syndrome with primary myelofibrosis, cirrhosis and ovarian cystic mass: A case report.

BACKGROUND: Turner syndrome (TS) with leukemia is a complicated clinical condition. The clinical course and outcome of these patients are poor, so the treatment and prognosis of TS with hematological malignancies deserve our attention. CASE SUMMARY: Here, we report a case of a 20-year-old woman diagnosed with TS, primary myelofibrosis (PMF), cirrhosis, and an ovarian cystic mass. This is the first report on the coexistence of TS and PMF with the MPL and SH2B3 mutations. The patient was diagnosed with cirrhosis of unknown cause, splenomegaly and severe gastroesophageal varices. Additionally, an ovarian cystic mass caused the patient to appear pregnant. The patient was treated with the JAK2 inhibitor-ruxolitinib according to peripheral blood cells, although myelofibrosis was improved, the splenomegaly did not reduce. Moreover, hematemesis and melena occasionally occurred. CONCLUSION: Ruxolitinib may clearly reduce splenomegaly. Though myelofibrosis was improved, cirrhosis and splenomegaly in this case continued to worsen. Effective treatment should be discussed.

All-trans Retinoic Acid, Arsenic Trioxide, and Anthracycline-based Chemotherapy Improves Outcome in Newly Diagnosed Acute Promyelocytic Leukemia Regardless of FLT3-ITD Mutation Status.

All-trans retinoic acid (ATRA) and pre-upfront arsenic trioxide (ATO) have revolutionized the therapy of acute promyelocytic leukemia (APL). However, internal tandem duplication of FMS-like tyrosine kinase 3 (FLT3-ITD) mutations is associated with increased risk of relapse. The aim of this study was to analyze the prognostic impact of FLT3-ITD on APL patients who received remission induction with ATRA, idarubicin (IDA) and/or ATO, followed by ATRA plus ATO along with anthracycline, as consolidation therapy. A total of 72 patients newly diagnosed with APL were included in this study. 83.3% of the patients achieved complete remission (CR) after induction therapy. FLT3-ITD mutations were detected in 16 (22.2%) patients and closely related to bcr-3 PML-RARa transcript (P<0.001). The 5-year overall survival (OS) rate was 100% in both FLT3-ITDpositive and FLT3-ITDnegative groups, and there was no significant difference in 5-year event-free survival (EFS) between the two groups (78.3% vs. 83.3%, P=0.85). ATRA plus ATO and anthracycline-based chemotherapy achieved great outcome in newly diagnosed APL regardless of the FLT3-ITD mutation status.

lncRNA FOXP4­AS1 predicts poor prognosis and accelerates the progression of mantle cell lymphoma through the miR­423­5p/NACC1 pathway.

Long non­coding RNA (lncRNA) forkhead box P4 antisense RNA 1 (FOXP4­AS1) has been determined to function as an oncogene in various types of cancer. However, the biological function and the underlying mechanisms of FOXP4­AS1 in mantle cell lymphoma (MCL) remain to be uncovered. The expression and the associated clinicopathological characteristics and prognostic significance of FOXP4­AS1 were explored in MCL clinical samples. The effects of FOXP4­AS1 on MCL cellular behaviors, including proliferation, migration and invasion were analyzed using CCK­8, crystal violet and Transwell assays. The downstream molecules of FOXP4­AS1 were explored using bioinformatics analysis and dual luciferase assay. Our results showed that FOXP4­AS1 expression was upregulated in MCL patients, and that the high expression of FOXP4­AS1 was correlated with the unfavorable prognosis of patients. Functionally, while FOXP4­AS1 downregulation inhibited proliferation, migration and invasion of MCL cells, FOXP4­AS1 overexpression had promotive effects on these cellular processes. Mechanistically, FOXP4­AS1 was found to act as a competing endogenous (ce)RNA for miR­423­5p to regulate the expression of nucleus accumbens­associated 1 (NACC1). The negative regulation of FOXP4­AS1 on miR­423­5p compared to that of miR­423­5p on NACC1 was determined at the mRNA or protein levels in MCL cells. Moreover, an inverse expression correlation between FOXP4­AS1 and miR­423­5p, and that between miR­423­5p and NACC1 was confirmed in MCL clinical samples. In addition, rescue assay showed that miR­423­5p upregulation or NACC1 knockdown abolished the promoting effects of FOXP4­AS1 on MCL cell proliferation, migration and invasion. In conclusion, FOXP4­AS1 promotes MCL progression through the upregulation of NACC1 expression by inhibiting miR­423­5p. FOXP4­AS1 may serve as a novel therapeutic target for patients with MCL.

[The Risk Factors of Thrombosis in Patients with Philadelphia Chromosome-negative Myeloproliferative Neoplasms].

OBJECTIVE: To investigate the overview of thrombosis in myeloproliferative neoplasms(MPN) patients, and to explore the risk factors of thrombosis at diagnosis and during follow-up. METHODS: The clinical data of 388 MPN patients treated in our hospital were collected. The patients were followed up by outpatient and phone. The risk factors of thrombosis were analyzed by statistical methods. RESULTS: Among 388 MPN patients, 161 patients (41.49%) showed thromboses at diagnosis or during follow-up. Among them, 92.55% were arterial thromboses, 146 cases (96.27%) were complicated with thromboses at diagnosis, and 36 cases (11.46%) showed newly thromboses or progression of previous thromboses among the 314 received full follow-up patients. Age (P＜0.001, HR:1.033, 95%CI:1.016-1.051), JAK2V617F mutation (P=0.037, HR:1.72, 95%CI: 1.033-2.862), hypertension (P＜0.001, HR:2.639, 95%CI:1.659-4.197) and hyperlipidemia (P＜0.001, HR:2.659, 95%CI:1.626-4.347) were the independent risk factors affecting thrombosis at diagnosis of the patients. During the follow-up, age (P=0.016, HR:1.032, 95%CI: 1.006-1.059) and previous thrombosis history (P=0.019, HR:2.194, 95%CI: 1.135-4.242) were the independent risk factors affecting the progression of thrombosis at different sites or on the basis of the previous thrombosis in the patients. CONCLUSION: Patients with advanced age, JAK2V617F mutation or complicated with hypertension and hyperlipidemia shows a higher risk of thrombosis at diagnosis, while the patients with advanced age or previous thrombosis history shows a higher risk of progression of thrombosis during the follow-up.

Fate of plastic film residues in agro-ecosystem and its effects on aggregate-associated soil carbon and nitrogen stocks.

Biodegradable (Bio) plastic films are widely viewed as promising alternative products of low-density polyethylene (LDPE) films to minimize plastic debris accumulation and pollution in agroecosystems. Yet, this speculation indeed lacks of sufficient evidences. We conducted a landfill investigation on the aging characteristics of Bio and LDPE plastic films in maize field, and the effects on soil aggregate composition and carbon & nitrogen stocks. The degradation rate of Bio film was up to 41.1% while that of LDPE film was zero. Scanning electron microscope (SEM) showed that the crack formation of Bio film had a pronounced domino effect, and FTIR showed that old Bio film displayed an extra wide peak threshold ranging from 3000 to 3500 cm-1. Particularly, the abundance of microplastics was elevated with the increased plastic residues, and the increment mostly resulted from Bio residues. Critically, plastic residues significantly lowered the soil macro-aggregates (>0.25 mm) proportion, while increasing that of micro-aggregates (0.1-0.25 mm) in LDPE, and silt/clay fraction (<0.1 mm) in Bio respectively. They significantly promoted total nitrogen content of the aggregates with the same size, but decreased the organic carbon content, dramatically lowering the C/N. Therefore, we first identified the fate of plastic film residues in agroecosystems and revealed the serious deficiencies of Bio plastic film.

An Immune Risk Score Predicts Survival of Patients with Acute Myeloid Leukemia Receiving Chemotherapy.

PURPOSE: Prediction models for acute myeloid leukemia (AML) are useful, but have considerable inaccuracy and imprecision. No current model includes covariates related to immune cells in the AML microenvironment. Here, an immune risk score was explored to predict the survival of patients with AML. EXPERIMENTAL DESIGN: We evaluated the predictive accuracy of several in silico algorithms for immune composition in AML based on a reference of multi-parameter flow cytometry. CIBERSORTx was chosen to enumerate immune cells from public datasets and develop an immune risk score for survival in a training cohort using least absolute shrinkage and selection operator Cox regression model. RESULTS: Six flow cytometry-validated immune cell features were informative. The model had high predictive accuracy in the training and four external validation cohorts. Subjects in the training cohort with low scores had prolonged survival compared with subjects with high scores, with 5-year survival rates of 46% versus 19% (P < 0.001). Parallel survival rates in validation cohorts-1, -2, -3, and -4 were 46% versus 6% (P < 0.001), 44% versus 18% (P = 0.041), 44% versus 24% (P = 0.004), and 62% versus 32% (P < 0.001). Gene set enrichment analysis indicated significant enrichment of immune relation pathways in the low-score cohort. In multivariable analyses, high-risk score independently predicted shorter survival with HRs of 1.45 (P = 0.005), 2.12 (P = 0.004), 2.02 (P = 0.034), 1.66 (P = 0.019), and 1.59 (P = 0.001) in the training and validation cohorts, respectively. CONCLUSIONS: Our immune risk score complements current AML prediction models.

Effects of sandy desertified land rehabilitation on soil carbon sequestration and aggregation in an arid region in China.

The rehabilitation of sandy desertified land in semi-arid and arid regions has a great potential to increase carbon sequestration and improve soil quality. Our objective was to investigate the changes in the soil carbon pool and soil properties of surface soil (0-15 cm) under different types of rehabilitation management. Our study was done in the short-term (7 years) and long-term (32 years) desertification control sites in a marginal oasis of northwest China. The different management treatments were: (1) untreated shifting sand land as control; (2) sand-fixing shrubs with straw checkerboards; (3) poplar (Populus gansuensis) shelter forest; and (4) irrigated cropland after leveling sand dune. The results showed that the rehabilitation of severe sandy desertified land resulted in significant increases in soil organic C (SOC), inorganic C, and total N concentrations, as well as enhanced soil aggregation. Over a 7-year period of revegetation and cultivation, SOC concentration in the recovered shrub land, forest land and irrigated cropland increased by 4.1, 14.6 and 11.9 times compared to the control site (shifting sand land), and increased by 11.2, 17.0 and 23.0 times over the 32-year recovery period. Total N, labile C (KMnO(4)-oxidation C), C management index (CMI) and inorganic C (CaCO(3)-C) showed a similar increasing trend as SOC. The increased soil C and N was positively related to the accumulation of fine particle fractions. The accumulation of silt and clay, soil C and CaCO(3) enhanced the formation of aggregates, which was beneficial to mitigate wind erosion. The percentage of >0.25 mm dry aggregates increased from 18.0% in the control site to 20.0-87.2% in the recovery sites, and the mean weight diameter (MWD) of water-stable aggregates significantly increased, with a range of 0.09-0.30 mm at the recovery sites. Long-term irrigation and fertilization led to a greater soil C and N accumulation in cropland than in shrub and forest lands. The amount of soil C sequestration reached up to 1.8-9.4 and 7.5-17.3 Mg ha(-1) at the 0-15 cm layer over a 7- and 32-year rehabilitation period compared to the control site, suggesting that desertification control has a great potential for sequestering soil C and improving soil quality in northwest China.

[Clinical Analysis of 269 Ph Chromosome-Negative Myeloproliferative Neoplasms Patients Stratified by Age].

OBJECTIVE: To investigate the difference of clinical characteristics between young patients(age≤40 years old) and middle-older patients(age>40 years old) with the myeloproliferative neoplasms（MPN）. METHODS: The clinical data (gene mutations， peripheral blood routine examinations， imaging examination and past history) of 269 MPN patients was collected and analyzed. RESULTS: In essential thrombocythemia (ET) group, the proportion of triple-negative type in young patients was higher than that in middle-older group, while the peripheral white blood cell（WBC） and platelets（PLT） counts in the first visit were lower. In polycythemia vera (PV) group, the total detection rate of JAK2V617F (80.65%) was lower than that of other research reports. Young patients with PV showed the lower JAK2V617F rate and lower WBC count, compared with the middle-older aged patients. Both CALR and MPL mutations were not found in PV patients. There was only 1 primary myelofibrosis (PMF) patient aged <40 years old. 91.67% of the patients merged splenomegaly and this rate was higher than that of ET or PV patients. It was found that there were a diagnosed familial MPN family and an undiagnosed family， and the youngest patient was only 8 years old. The second-generation gene sequencing detection for them was not carried out. CONCLUSION: Age is an important reference index in the assessment of risks. The MPN patients with different age and types show much difference in gene mutations, peripheral blood cell counts, thrombotic events and sizes of spleen. The onset ages of patients with familial MPN trends to be generational younger.

Changes in soil aggregate, carbon, and nitrogen storages following the conversion of cropland to alfalfa forage land in the marginal oasis of northwest China.

Maintenance of soil organic carbon (SOC) is important for sustainable use of soil resources due to the multiple effects of SOC on soil nutrient status and soil structural stability. The objective of this study was to identify the changes in soil aggregate distribution and stability, SOC, and nitrogen (N) concentrations after cropland was converted to perennial alfalfa (Medicago sativa L. Algonguin) grassland for 6 years in the marginal oasis of the middle of Hexi Corridor region, northwest China. Significant changes in the size distribution of dry-sieving aggregates and water-stable aggregates, SOC, and N concentrations occurred after the conversion from crop to alfalfa. SOC and N stocks increased by 20.2% and 18.5%, respectively, and the estimated C and N sequestration rates were 0.4 Mg C ha(-1) year(-1) and 0.04 Mg N ha(-1) year(-1) following the conversion. The large aggregate (>5 mm) was the most abundant dry aggregate size fraction in both crop and alfalfa soils, and significant difference in the distribution of dry aggregates between the two land use types occurred only in the >5 mm aggregate fraction. The percentage of water-stable macroaggregates (>2, 2-0.25 mm) and aggregate stability (mean weight diameter of water-stable aggregates, WMWD) were significantly higher in alfalfa soils than in crop soils. There was a significant linear relationship between total SOC concentration and aggregate parameters (mean weight diameter) for alfalfa soils, indicating that aggregate stability was closely associated with increased SOC concentration following the conversion of crops to alfalfa. The SOC and N concentrations and the C/N ratio were greatest in the >2 mm water-stable aggregates and the smallest in the 0.25-0.05 mm aggregates in crop and alfalfa soils. For the same aggregate, SOC and N concentrations in aggregate fractions increased with increasing total SOC and N concentrations. The result showed that the conversion of annual crops to alfalfa in the marginal land with coarse-texture soils can significantly increase SOC and N stocks, and improve soil structure.

[Evolutionary characteristics of soil organic carbon storage in soil plough layer under a cropland reclamation process in desert oasis]. / è’æ¼ ç»¿æ´²å†œç”°åž¦æ®–è¿‡ç¨‹ä¸­è€•å±‚åœŸå£¤ç¢³å‚¨é‡æ¼”å˜ç‰¹å¾.

The reclamation time was examined by combining field investigation and remote sensing image analysis in the Linze desert oasis area in the middle of the Hexi Corridor. Characteristics of soil organic carbon storage (SOCD) in cropland (0-20 cm) with different reclamation backgrounds were compared to understand the evolution trend of SOCD during reclamation. The SOCD of cropland (0-20 cm) varied from 2.41 to 32.97 t·hm-2, with an average of 17.22 t·hm-2. The ave-rage SOCD of cropland in saline-alkali land, Gobi and sandy land background was 19.36, 16.10, and 15.93 t·hm-2, respectively. The SOCD under three different reclamation conditions showed an increasing trend after cultivation. The cropland in sandy land and the Gobi background slowly increased after 20 years reclamation. The cropland in saline-alkali background showed a slowdown after 25 years reclamation. The SOC sequestration rates of the cropland under sandy land, Gobi and saline-alkali land background were 0.424, 0.485 and 0.811 t·hm-2·a-1, respectively. The SOCD were positively correlated with total nitrogen, total phosphorus, available nitrogen, and available phosphorus content, but had no significant correlation with available potassium and soil pH. In conclusion, the SOC sequestration rate in the saline-alkali land background was significantly higher than that in Gobi and sandy land background. However, SOCD were at a relatively low level after 30 years reclamation. Therefore, cropland management needs to be carried out for different reclamation backgrounds to improve land use efficiency and productivity in desert oasis.

BCL2/Ki-67 index predict survival in germinal center B-cell-like diffuse large B-cell lymphoma.

Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma. BCL2 apoptosis regulator (BCL2) and marker of proliferation Ki-67 (Ki-67) are established prognostic markers, which have traditionally been assessed separately in DLBCL. However, no studies have evaluated the prognostic value of the combination of BCL2 and Ki-67 index. Thus, the present study aimed to analyze the prognostic value of combination of these two markers. Immunohistochemical analysis was used to assess the expression of BCL2 and Ki-67 in 274 cases of DLBCL. The BCL2/Ki-67 index demonstrated a significant association with decreased overall and progression free survival of patients with DLBCL, particularly for the germinal center B-cell-like subtype of DLBCL. Following multivariate analysis, the BCL2/Ki-67 index retained prognostic significance. Patients with coexpression of BCL2 and Ki-67 constituted a unique group with poor survival, thus novel therapies targeting BCL2 protein and high proliferative activity may improve the outcome of these patients.

[Effect of soil texture in unsaturated zone on soil nitrate accumulation and groundwater nitrate contamination in a marginal oasis in the middle of Heihe River basin].

In irrigated agricultural ecosystems, the accumulation, distribution and transfer of nitrate nitrogen (NO(3-)-N) in soil profile and groundwater nitrate pollution were influenced by irrigation and fertilization, and were closely related to soil textural characteristics. In this study, a monitoring section with 10 groundwater observation wells along Heihe River flood land-old oasis croplands-newly cultivated sandy croplands-fixed sandy land outside oasis was established in Pingchuan desert-oasis in Linze county in the middle of Heihe river basin, and groundwater NO(3-)-N concentration was continuously monitored. Soil texture and NO(3-)-N concentration in the unsaturated zone at different landscape locations were determined. The NO(3-)-N transfer change in soil profile, nitrate leaching of soils with different texture and fertility levels in the 0-100 cm layer were analyzed. The results indicated that the vertical distribution of soil texture was sandy loam in the 0-130 cm depth, loam in the 130-190 cm and clay loam in the 190-300 cm for the old oasis croplands. For newly cultivated sandy croplands, sand content was more than 80% in each soil layer of the 0-300 cm profile, although a thin clay layer occurred in the 140-160 cm depth. The clay layer occurred 160 cm below the sand-fixing zone outside oasis. There were significant correlations between soil NO(3-)-N concentration and silt + clay content, and the order of significant degree was the natural soils of sandy lands > the newly cultivated sandy croplands > the old oasis croplands. The loss of N leaching was closely correlated to the silt + caly content in the 0-100 cm soil depth. The groundwater NO(3-)-N concentration varied from 1.01 to 5.17 mg · L(-1), with a mean value of 2.65 mg · L(-1) and from 6.6 to 29.5 mg · L(-1), with an average of 20.8 mg · L(-1) in the area of old oasis croplands and the newly cultivated croplands, respectively. The averaged groundwater NO(3-)-N concentration in the area of newly cultivated sandy croplands during the period of May and October, 2013 was 26.5 mg · L(-1), which was increased by 9.5 mg · L(-1) in comparison with the same period of 2012. There was a clear increasing trend in groundwater NO(3-)-N concentration in the sand-fixing zone outside oasis. The textural characteristics of soil unsaturated zone in the shallow groundwater distribution area was the key determining factor for controlling soil NO(3-)-N leaching and groundwater nitrate pollution. The newly cultivated sandy croplands were the nitrate vulnerable zones and high-risk areas of groundwater nitrate pollution. The implementation of cultivation pattern and irrigation and fertilization management that could effectively reduce groundwater NO(3-)-N pollution should be considered in the development of ecological agriculture.

[Characteristics of soil nematode community along an age sequence of sandy desert soil cultivation in a marginal oasis of middle reaches of Heihe River].

This paper studied the characteristics of soil nematode community following the conversion of native sandy desert soil to irrigated farmland in a marginal oasis of the middle reaches of Heihe River basin, aimed to approach the bioindicating function of soil nematodes in soil evolution process. A total of 27921 soil nematode individuals were captured, belonging to 25 families and 34 genera. The total number of nematodes increased gradually with increasing age of cultivation. At all sampling sites, bacterivores and plant parasites were the dominant trophic groups, and made up the main parts of nematode community in oasis farmland. Through the analysis of the evenness index (J) and dominance index (lambda) of nematode community, the ecosystems were found to be fragile for the farmlands having cultivated for 0, 10, and > 50 years. The maturity index MI2-5 and MMI decreased with increasing cultivation age, suggesting that the practice of agricultural use enhanced the disturbance on farmland. The soil properties changed significantly after 10 years of cultivation, which was at a significant change stage for the structure stability of soil ecosystems. The characteristics of soil nematode community could be used as the bioindicator of soil evolution following the conversion of native desert soil to irrigated farmland.

[Effects of farmland use type and winter irrigation on nitrate accumulation in sandy farmland soil].

With the sandy farmland in the marginal oasis in middle reaches of Heihe River Basin, Northwest China as test object, this paper studied soil NO3- -N accumulation and leaching under effects of different farmland use type and winter irrigation. The results showed that the mean NO3- -N concentration in 0-300 cm soil profile in different farmlands ranged from 1.27 mg x kg(-1) to 83.60 mg x kg(-1) Soil NO3- -N concentration was higher in 0-40 cm and 135-300 cm layers, but lower in 40-135 cm layer. Greenhouse vegetable field had a significantly higher soil NO3- -N concentration than the other farmland use types. The accumulated amount of soil NO3- -N decreased in the order of greenhouse vegetable field > tomato field > cotton field > seed maize field > maize-wheat rotation field > maize-wheat stripe intercropping field > alfalfa field > jujube plantation. The NO3- -N accumulation in 0-300 cm soil profile in greenhouse vegetable filed reached 2171.45 kg x hm(-2), which would be a serious menace to groundwater quality, followed by tomato field and cotton field. Lesser accumulation of soil NO3- -N was found in seed maize field, maize-wheat intercropping field, maize-wheat rotation field, alfalfa field, and jujube plantation, but its pollution potential would not be neglected. After winter irrigation, soil NO3- -N concentration decreased in 0-80 cm layer but increased in 80-300 cm layer, indicating that winter irrigation caused NO3- -N leaching into deeper soil depth. The leached amount of soil NO3- -N to deeper layers increased with increasing amount of winter irrigation. To mitigate soil NO3- -N leaching and groundwater contamination, a comprehensive consideration should be made on the rational arrangement of farmland use type, proper decrease of planting N-accumulated crops, and reasonable winter irrigation.

[Hydrochemical characteristics and spatial-temporal variation of mineralization for the groundwater in Minqin oasis].

In order to curb the deterioration of ecological environment and promote the economic and social sustainable development of Shiyang River Basin, the Minqin government implemented water-saving measures of the shut-in and pressure fields and water discharge engineering in Shiyang River downstream in 2001 and in 2006, respectively. Sixty-five groundwater samples were collected in Minqin County in 2008 and the concentrations of major ions were analyzed in laboratory. The hydrochemistry characteristic of the groundwater was studied by traditional statistical analysis method. Results indicated the concentrations of the major ions, such as SO4(2-), Cl-, HCO3, CO3(2-), Na+, Mg2+, Ca2+ and K+ in the groundwater samples, were (921 +/- 1042), (241 +/- 211), (282 +/- 123), (4.7 +/- 11.7), (468 +/- 599), (156 +/- 166), (142 +/- 89) and (17.6 +/- 34.5) mg/L, respectively. There was increasing tendency for major ion concentrations along the groundwater flow direction. The groundwater mineralization was (2.2 +/- 1.9) g/L in 2008. The type of water samples in Minqin oasis mainly belonged to SO4(2-) - Cl- -Na+ -Mg2+. The average concentration of the NO3- was (8.1 +/- 9.9) mg/L in the groundwater of Minqin, and the nitrate-N content was over 10 mg/L in 1.54% of all of water samples, which was unsuitable for drinking. Based on the data of groundwater mineralization in 2002, 2005 and 2008, the spatial-temporal variations of groundwater mineralization were studied by geo-statistical analysis method. Kringing interpolation results showed that groundwater mineralization at the spatial distribution scale were took on a gradual increase pattern from south to north. As for the change trend of groundwater mineralization in south area of Minqin County, there was increasing trend from 2002 to 2005, but decreasing trend was occurred from 2005 to 2008. Change trend of groundwater mineralization in north area of Minqin oasis was opposite to that of in south area. There was decreasing trend for the groundwater mineralization in south area from 2005 to 2008, which was due to the impact on water discharge in Shiyang River Basin. There was no significant improvement for groundwater by single water-saving measure, but the quality of groundwater was improved after water discharge in Shiyang River Basin.

[Soil carbon and nitrogen sequestration following cropland to forage grassland conversion in the marginal land in the middle of Heihe River basin, northwest China].

Changes in soil organic carbon (SOC) and total nitrogen (TN) stocks were studied following croplands were converted to forage grasslands (alfalfa) for five years on the marginal land at the edge of oasis in the middle reaches of Heihe river basin. Soil from 12 paired forage land/adjacent cropland on the two soil types (Typic Torripsamments and Typic Calciorthids) was sampled at the three depths of 0-5, 5-10 and 10-20 cm and analyzed for SOC and TN, particulate organic carbon (POC) and nitrogen (PON). The studied soils had very low SOC and N concentrations. SOC stock at the 0-20 cm depth increased by 22.1%-27.8% after conversion of annually crop to perennial alfalfa for four years, and carbon sequestration rate was estimated to be on average 0.47 Mg/(hm2 x a). The greatest change in SOC stock occurred at the 0-5 cm surface layer with an increase of 32%-66%. No significant TN stock was found at the 0-20 cm depth, however, it increased at the 0-5 cm surface layer by 12.8% and 48.1% for Typic Torripsamments and Typic Calciorthids, respectively. Changes in POC and PON stocks were more significant than those in SOC and total N following conversion of crop to forage, and the percentage of distributions of POC and PON increased. POC and PON stocks at the 0-20 cm depth increased by 22.8%-42.7% and 18.6%-57.6% with the greatest increases at the 0-5 cm layer. The increase in soil C pool was mainly attributed to the increase of POC formation after the marginal lands converted to perennial forage cover. Typic Calciorthids with lower SOC concentration had relatively lower C sequestration rate but more significant effects of C and N sequestration compared with Typic Torripsamments.

Changes in soil properties after establishment of Artemisia halodendron and Caragana microphylla on shifting sand dunes in semiarid Horqin Sandy Land, northern China.

In the semiarid Horqin sandy land of northern China, establishment of artificial sand-fixing shrubs on desertified sandy lands is an effective measure to control desertification and improve the regional environment. Caragana microphylla Lam. and Artemisia halodendron Turcz. ex Bess. are two of the dominant native shrub species, which are adapted well to windy and sandy environments, and thus, are widely used in revegetation programs to control desertification in Horqin region. To assess the effects of artificially planting these two shrub species on restoration of desertified sandy land, soil properties and plant colonization were measured 6 years after planting shrubs on shifting sand dunes. Soil samples were taken from two depths (0-5 cm and 5-20 cm) under the shrub canopy, in the mid-row location (alley) between shrub belts, and from nonvegetated shifting sand dune (as a control). Soil fine fractions, soil water holding capacity, soil organic C and total N have significantly increased, and pH and bulk density have declined at the 0-5-cm topsoil in both C. microphylla and A. halodendron. At the 5-20 cm subsurface soil, changes in soil properties are not significant, with exception of bulk density and organic C concentration under the canopy of A. halodendron and total N concentration under the canopy of C. microphylla. Soil amelioration processes are initiated under the shrub canopies, as higher C and N concentrations were found under the canopies compared with alleys. At the same time, the establishment of shrubs facilitates the colonization and development of herbaceous species. A. halodendron proved to have better effects in fixing the sand surface, improving soil properties, and restoring plant species in comparison to C. microphylla.