This page has only limited features, please log in for full access.
Data on the dynamics of Olsen-P in deep soil profiles are crucial for improving P use efficiency but remain scarce worldwide. Hence, we sampled sixty 6-m-deep soil profiles from farmland and in 8-yr, 17-yr, and 25-yr-old apple orchards on China’s Loess Plateau, and aimed to investigate the vertical distribution of soil Olsen-P following the farmland-to apple orchard conversion. Land-use change from farmland to apple orchard significantly affected Olsen-P at 0–40 cm soil, with the concentration generally increasing with age of apple orchard. By contrast, Olsen-P at 40–600 cm was not significantly different among the cropping systems. In both farmland and apple orchards, the concentration of Olsen-P decreased at 40–100 cm, compared with that in the 0–40 cm layer, increased with depth from 100 to 400 cm and then stabilized from 400 to 600 cm. The highest accumulation of residual soil Olsen-P in the 6-m profile (RSP0−600) was in the 25-yr orchard, followed by the 17-yr and 8-yr orchards, with the lowest accumulation in farmland. The differences in RSP0−600 cm were primarily associated with RSP0−100 cm, which was significantly positively related to the accumulative application of P fertilizer. The change point in soil Olsen-P against P leaching was 71.2 mg kg−1, but in farmland and 8-yr, 17-yr, and 25-yr apple orchards, the averaged-depth contents of Olsen-P were all below the critical value, indicating no P leaching risk. Regression analysis revealed that the vertical distribution of soil Olsen-P was regulated by P fertilization at 0–100 cm and by crop roots at 100–600 cm, irrespective of cropping system. The insights gained on Olsen-P accumulation and migration within deep soil profiles after the farmland-to-apple orchard conversion can help to optimize land use and P fertilization management in major apple-producing countries with burgeoning growth in apple production.
Zhanjun Liu; Liyao Hou; Yuanjun Zhu; Xinpeng Xu. Vertical distribution and regulation of Olsen-phosphorus in 6-m soil profiles after farmland-to-apple orchard conversion on the Chinese Loess Plateau. CATENA 2021, 202, 105254 .
AMA StyleZhanjun Liu, Liyao Hou, Yuanjun Zhu, Xinpeng Xu. Vertical distribution and regulation of Olsen-phosphorus in 6-m soil profiles after farmland-to-apple orchard conversion on the Chinese Loess Plateau. CATENA. 2021; 202 ():105254.
Chicago/Turabian StyleZhanjun Liu; Liyao Hou; Yuanjun Zhu; Xinpeng Xu. 2021. "Vertical distribution and regulation of Olsen-phosphorus in 6-m soil profiles after farmland-to-apple orchard conversion on the Chinese Loess Plateau." CATENA 202, no. : 105254.
Mulching and nitrogen (N) fertilization are essential to increase crop yields in semiarid drylands. However, their long-term effects on soil physicochemical properties, extracellular enzyme activities, microbial community structure, and therefore soil quality via developing a soil quality index (SQI) remain largely unexplored. Hence, we analyzed soils after 14 years of mulching (CT, no mulch; RF, plastic film-mulched ridges and straw mulched-furrows; SM, straw mulching) and N fertilization (0, 120 and 240 kg ha−1) treatments in a maize–wheat rotation on China's Loess Plateau. Compared with CT, RF and SM significantly increased soil moisture content (SMC), organic carbon (SOC), phosphatase, and total phospholipid fatty acids (PLFAs). Compared with RF, SM increased SOC, total N, available phosphorus (AP), available potassium (AK), β-glucosidase, N-acetyl-glucosaminidase (NAG), peroxidase, and cellobiohydrolase, gram-negative bacteria (G−), and fungi. Consequently, the SQI was highest in SM (0.698), followed by RF (0.642) and CT (0.620). Nitrogen fertilization significantly increased total N, NO3−, microbial biomass N, α-glucosidase, NAG, total PLFAs, and G−, but caused a significant decline in pH, AP, AK, and the G+:G− ratio. Averaged across N-fertilizations, the SQI was ranked N240 (0.680) > N120 (0.650) > N0 (0.630). Redundancy analysis showed that SOC was closely associated with enzyme activities, whereas NO3−, SOC, and SMC were the key variables regulating microbial community composition. Structural equation model indicated that mulching and N fertilization strongly and positively affected SQI by regulating soil available N, P, and K, enzyme activities, and microbial communities, and the total effect of mulching (0.62) on SQI was greater than that of N addition (0.34). Collectively, the highest SQI observed in the SM + N240 treatment suggested that straw mulch, rather than plastic-film mulch, combined with high N addition could be a sustainable land management practice that improves soil quality in semiarid dryland farming systems.
Qiuyu Chen; Zhanjun Liu; Jianbin Zhou; Xinpeng Xu; Yuanjun Zhu. Long-term straw mulching with nitrogen fertilization increases nutrient and microbial determinants of soil quality in a maize–wheat rotation on China's Loess Plateau. Science of The Total Environment 2021, 775, 145930 .
AMA StyleQiuyu Chen, Zhanjun Liu, Jianbin Zhou, Xinpeng Xu, Yuanjun Zhu. Long-term straw mulching with nitrogen fertilization increases nutrient and microbial determinants of soil quality in a maize–wheat rotation on China's Loess Plateau. Science of The Total Environment. 2021; 775 ():145930.
Chicago/Turabian StyleQiuyu Chen; Zhanjun Liu; Jianbin Zhou; Xinpeng Xu; Yuanjun Zhu. 2021. "Long-term straw mulching with nitrogen fertilization increases nutrient and microbial determinants of soil quality in a maize–wheat rotation on China's Loess Plateau." Science of The Total Environment 775, no. : 145930.
Data on fertilization and spatial characterization of soil chemical properties are crucial for developing sustainable apple production systems. However, such information at regional scale is scarce. We conducted a survey asking farmers in Luochuan County about their current use of fertilizers, and collected 290 soil samples from 0 to 20 cm and 20–40 cm depths, respectively, to examine the spatial variability of eight chemical properties, and analyze the possible relations between soil quality index (SQI), apple yield, and stand age. Results showed apple orchards were severely overfertilized, with chemical N-P2O5-K2O fertilizers of 1230–795–1080 kg ha−1 yr−1 and organic fertilizers applied at the rates of 74.7 kg N ha−1 yr−1, 66.1 kg P2O5 ha−1 yr−1, and 75.8 kg K2O ha−1 yr−1. With the exception of pH, both coefficient of variation and variogram range showed a moderate to high variability (16.5–77.7%) and spatial dependency (7.10–47.8%) for selected parameters. Distribution maps illustrated that the 0–20 cm soil depth was characterized by typically higher soil nutrient contents compared with that of 20–40 cm depth. Relative to the data observed in the 1980s, the averaged pH values decreased by ~0.20 units across 0–40 cm depth, while soil organic matter, total N, available N, P, K and Zn, and exchangeable Ca (Ex-Ca) increased markedly (26.2–508%) in the 0–20 cm depth, whilst few changes ( 9.84–178%) occurred at 20–40 cm depth. Correlation analysis revealed that Ex-Ca was the unique variable that was significantly (P < 0.05) correlated with apple yield at 0–20 cm depth, suggesting the importance of soil Ex-Ca as an indicator of apple production. The relationship between apple yield and stand age was well described by a parabolic model, with ~17 years as the optimal stand age for producing the maximum apple yield. Notably, the SQI scores had significant relationships with apple yields for 8–13, 14–17 and 18–31-yr-old stands in the 0–20 cm depth, but the relationship was only significant for the 14–17-yr-old stands in the 20–40 cm depth, implying that 0–20 cm is the appropriate sampling depth for evaluating soil quality changes in apple production systems. Overall, long-term fertilization improved soil fertility of apple orchards, which required particular attention with regard to overuse of N, P and K fertilizers. Those results provide an important reference for China and other major apple-producing countries.
Liyao Hou; Zhanjun Liu; Jiarui Zhao; Pengyi Ma; Xinpeng Xu. Comprehensive assessment of fertilization, spatial variability of soil chemical properties, and relationships among nutrients, apple yield and orchard age: A case study in Luochuan County, China. Ecological Indicators 2020, 122, 107285 .
AMA StyleLiyao Hou, Zhanjun Liu, Jiarui Zhao, Pengyi Ma, Xinpeng Xu. Comprehensive assessment of fertilization, spatial variability of soil chemical properties, and relationships among nutrients, apple yield and orchard age: A case study in Luochuan County, China. Ecological Indicators. 2020; 122 ():107285.
Chicago/Turabian StyleLiyao Hou; Zhanjun Liu; Jiarui Zhao; Pengyi Ma; Xinpeng Xu. 2020. "Comprehensive assessment of fertilization, spatial variability of soil chemical properties, and relationships among nutrients, apple yield and orchard age: A case study in Luochuan County, China." Ecological Indicators 122, no. : 107285.
Silicon (Si) enhances maize resistance to drought. While previous studies have mainly focused on the seedling stage, the mediation of drought stress by Si imposed at the vegetative and reproductive stages has been rarely investigated. A soil-column experiment was thus conducted under a rainproof shelter to quantify the effect s of Si application on the physiological and agronomic responses of maize to drought stress imposed at the 6-leaf (D-V6), 12-leaf (D-V12), and blister (D-R2) stages. The observed parameters included plant growth, photosynthesis, osmolytes, antioxidant activity, and grain yield. The results showed that drought stress strongly decreased the leaf area, leaf water content, photosynthetic rate, chlorophyll content, and antioxidant activity (superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT)) and markedly increased lipid peroxidation. D-V6, D-V12, and D-R2 decreased grain yields by 12.9%, 28.9%, and 44.8%, respectively, compared to the well-watered treatment (CK). However, Si application markedly increased leaf area, chlorophyll content, photosynthetic rate, osmolyte content, and enzymatic antioxidant activities (SOD, POD, and CAT), and decreased malondialdehyde (MDA) and superoxide radical accumulation, ultimately improving maize yields by 12.4%, 69.8%, and 80.8%, respectively, compared to the non-Si treated plants under drought stress at the V6, V12, and R2 stages. Furthermore, maize yields had a significant positive correlation with chlorophyll content and SOD and POD activity during the three stages. Our findings suggest that Si-induced changes in chlorophyll content and antioxidant activity might constitute important mechanisms for mitigating drought stress. In conclusion, this study provides physico-biochemical evidence for the beneficial role of Si in alleviating drought-induced yield reduction in maize, particularly during the late vegetative or early reproductive stages. Thus, Si application constitutes an effective approach for improving maize yield in rain-fed agricultural systems.
Dongfeng Ning; Anzhen Qin; Zhandong Liu; Aiwang Duan; Junfu Xiao; Jiyang Zhang; Zugui Liu; Ben Zhao; Zhanjun Liu. Silicon-Mediated Physiological and Agronomic Responses of Maize to Drought Stress Imposed at the Vegetative and Reproductive Stages. Agronomy 2020, 10, 1136 .
AMA StyleDongfeng Ning, Anzhen Qin, Zhandong Liu, Aiwang Duan, Junfu Xiao, Jiyang Zhang, Zugui Liu, Ben Zhao, Zhanjun Liu. Silicon-Mediated Physiological and Agronomic Responses of Maize to Drought Stress Imposed at the Vegetative and Reproductive Stages. Agronomy. 2020; 10 (8):1136.
Chicago/Turabian StyleDongfeng Ning; Anzhen Qin; Zhandong Liu; Aiwang Duan; Junfu Xiao; Jiyang Zhang; Zugui Liu; Ben Zhao; Zhanjun Liu. 2020. "Silicon-Mediated Physiological and Agronomic Responses of Maize to Drought Stress Imposed at the Vegetative and Reproductive Stages." Agronomy 10, no. 8: 1136.
Imbalanced fertilization without potassium (K) is a worldwide phenomenon in K-rich soils, but its long-term effects on soil quality are poorly understood. Here, in a wheat–fallow system with K-rich soil, soil nutrients and enzyme activities involved in C, N, P, and S cycling and microbial community composition were studied in a 27-year field study with three treatments: no fertilizer (CK); mineral N and P fertilizer (NP); and mineral N, P, and K fertilizer (NPK). Results revealed that long-term NP and NPK fertilization significantly increased soil quality index (SQI) scores and wheat grain yield by mediating soil fertility, which was characterized by a significant decline in soil pH and increase in soil organic carbon (SOC), total N, available N (AN), available P (AP), enzymatic activities, and the abundance of total bacteria, fungi, and actinomycetes, when compared to CK. NP exhibited significantly higher SOC, AN, AP, microbial biomass C (MBC) and N (MBN), N-acetyl-glucosaminidase, total bacteria, and fungi values compared to NPK; the opposite was true for soil pH and available K. Notably, the differences in wheat grain yield were not statistically significant, while SQI scores in NP (0.86 ± 0.02) were appreciably higher than NPK (0.79 ± 0.03), which was attributed to the differences in MBC, MBN, and microbial communities. Redundancy analysis (RDA) indicated that SOC was the key variable affecting enzymatic activities and microbial community composition. The partial least squares path model (PLS-PM) revealed that fertilization-induced changes in SQI were primarily associated with soil microbiological properties (e.g., microbial community composition), while fertilization-driven increases in wheat grain yield were regulated by the soil nutrients. These results suggest that long-term NPK fertilization decreases soil biological quality in K-rich soils, and further studies are required to elucidate the underlying mechanisms by which K affects soil quality in agricultural systems.
Qiuyu Chen; Ying Xin; Zhanjun Liu. Long-Term Fertilization with Potassium Modifies Soil Biological Quality in K-Rich Soils. Agronomy 2020, 10, 771 .
AMA StyleQiuyu Chen, Ying Xin, Zhanjun Liu. Long-Term Fertilization with Potassium Modifies Soil Biological Quality in K-Rich Soils. Agronomy. 2020; 10 (6):771.
Chicago/Turabian StyleQiuyu Chen; Ying Xin; Zhanjun Liu. 2020. "Long-Term Fertilization with Potassium Modifies Soil Biological Quality in K-Rich Soils." Agronomy 10, no. 6: 771.
The cropland-to-apple orchard conversion is expanding in the semiarid Loess Plateau, yet its impacts on deep soil moisture and nitrate are poorly documented. This study was conducted in Luochuan, typically the best area for apple planting in China, where fifteen 6-m-deep soil profiles were sampled from each cropland (as the control), as well as 8-, 17- and 25-yr apple orchards, to investigate the vertical distributions of soil moisture and nitrate and their storage. Results showed that the 8-yr apple orchards were comparable to cropland in soil moisture content (SMC), soil water storage (SWS), soil nitrate concentration (SNC) and residual soil nitrate (RSN). In contrast, 17- and 25-yr apple orchards, caused serious SWS deficits, of 140 mm and 150 mm, and substantially increased RSN, by 4270 and 7250 kg N ha−1, respectively, when compared with cropland. Notably, RSN in deep soils was strongly enhanced by the stand age of apple orchard, which was primarily associated with accumulated N fertilizer inputs. Similar SNCs in the 540–600 cm layer among land use types implied a 6-m-deep soil profile might be robust for evaluating NO3− dynamics following cropland-to-orchard conversion in the study region. Regression relationships between RSN and SWS were significantly positive in the 100–300 cm soil layer under cropland but significantly negative in the 0–100 cm and 100–300 cm layers under 8-yr apple orchards, indicating distinct hydrological processes of NO3− under differing land uses. In conclusion, converting cropland to apple orchards could result in soil moisture decline and nitrate accumulation in the 6-m profile that may threaten the Loess Plateau's sustainability. Therefore, integrated water and N management should be practiced to mitigate the unfavorable impacts and develop sustainable apple production in China and other semiarid areas of the world.
Zhanjun Liu; Pengyi Ma; Bingnian Zhai; Jianbin Zhou. Soil moisture decline and residual nitrate accumulation after converting cropland to apple orchard in a semiarid region: Evidence from the Loess Plateau. CATENA 2019, 181, 104080 .
AMA StyleZhanjun Liu, Pengyi Ma, Bingnian Zhai, Jianbin Zhou. Soil moisture decline and residual nitrate accumulation after converting cropland to apple orchard in a semiarid region: Evidence from the Loess Plateau. CATENA. 2019; 181 ():104080.
Chicago/Turabian StyleZhanjun Liu; Pengyi Ma; Bingnian Zhai; Jianbin Zhou. 2019. "Soil moisture decline and residual nitrate accumulation after converting cropland to apple orchard in a semiarid region: Evidence from the Loess Plateau." CATENA 181, no. : 104080.
Appropriate water-saving and nitrogen management strategies are critical for achieving sustainable agricultural development in dry sub-humid areas of the Chinese Loess Plateau. The present study was conducted in 2004, 2005, 2008, and 2012 based on a long-term field experiment and aimed to investigate the coupled impacts of mulching and N fertilization on maize yield, water use efficiency (WUE), and residual soil nitrate (RSN) accumulated in the soil profile (0–200 cm). The results demonstrated that mulch is conducive to increasing summer maize yield. The plastic film-mulched ridge and straw-mulched furrow (RF) treatment significantly increased maize yield across the studied period, while the straw mulch (SM) treatment did not significantly increase maize yield until the third experimental year. Compared with SM, the RF treatment showed more significant and positive effects on maize yield, WUE, and RSN accumulated in the 0–200 cm soil depth. N fertilization significantly increased maize yield and WUE, but no significant differences were observed when 120 and 240 kg N ha−1 were applied. The N240 treatment was characterized by relatively high NO3−-N accumulation in 0–200 cm soil depth and low ratios of soil nitrate in the upper to the lower soil layers, indicating a considerable potential for NO3−-N leaching. Averaged across years, economic optimum N fertilizer rates (Nops) were 154, 148, and 150 kg N ha−1 for the no mulch, RF, and SM treatments, respectively. This suggested that 25.8–51.2% of N rate can be reduced while maintaining an acceptably high maize yield. Additionally, understanding NO3−-N depth distribution in 0–100 cm soil profile can adequately predict and represent the characteristics of NO3−-N accumulated in the 100–200 cm and 0–200 cm soil layers because of their significant correlations, thus saving time and money. In conclusion, the practice of RF combined with properly reduced farmers’ N rate (~ 150 kg N ha−1) is the preferred option for maize production in the Chinese Loess Plateau, and further research is required to investigate the effects of mulching on summer maize under Nop conditions.
Zhanjun Liu; Yan Meng; Miao Cai; Jianbin Zhou. Coupled effects of mulching and nitrogen fertilization on crop yield, residual soil nitrate, and water use efficiency of summer maize in the Chinese Loess Plateau. Environmental Science and Pollution Research 2017, 24, 25849 -25860.
AMA StyleZhanjun Liu, Yan Meng, Miao Cai, Jianbin Zhou. Coupled effects of mulching and nitrogen fertilization on crop yield, residual soil nitrate, and water use efficiency of summer maize in the Chinese Loess Plateau. Environmental Science and Pollution Research. 2017; 24 (33):25849-25860.
Chicago/Turabian StyleZhanjun Liu; Yan Meng; Miao Cai; Jianbin Zhou. 2017. "Coupled effects of mulching and nitrogen fertilization on crop yield, residual soil nitrate, and water use efficiency of summer maize in the Chinese Loess Plateau." Environmental Science and Pollution Research 24, no. 33: 25849-25860.