• Authors:
    • Smirnova, N. V.
    • Nechaeva, T. V.
    • Yakutina, O. P.
  • Source: AGRICULTURE ECOSYSTEMS & ENVIRONMENT
  • Volume: 200
  • Year: 2015
  • Summary: Snowmelt erosion is one of the reasons for the decreasing soil fertility in the most valuable agricultural lands in the south of West Siberia. The aim of this study was to examine the influence of long term soil use and degree of soil erosion on the main fertility indicators of Greyzemic Phaeozem (30-year fallow, non-eroded, slightly eroded, moderately eroded and strongly eroded). Soils were analysed for organic carbon (SOC), pH w, cation-exchange capacity and total and available forms of nitrogen, phosphorus and potassium. Plants were analysed for sheaf and grain yield and NPK content of wheat. A decrease in the content of the total forms of carbon and nitrogen and an increase in the C/N ratio were observed with an increase in the degree of soil erosion. SOC losses in the ploughed layer of slightly, moderately and strongly eroded soils were 6.6, 13 and 27%, respectively, while the nitrogen losses were 5, 33, and 71%. The widest (37) C/N ratio was found in strongly eroded soil. The content of total phosphorus in the ploughed layer of slightly, moderately and strongly eroded soils decreased by 3.8, 23 and 15.4%, respectively, in comparison with non-eroded soil. Available forms of phosphorus and potassium increased with an increase in the degree of soil erosion, with the highest values found in moderately eroded soil. Exchangeable K/available K ratio, the overall mobility of potassium in the eroded soils also increased. The highest plant productivity was found on moderately eroded soil. A deterioration of the nitrogen regime led to a narrowing of the N/K ratio from 2.4 (grain) and 0.4 (straw) up to 1.9 (grain) and 0.3 (straw) for non-eroded and strongly eroded soils respectively. A critical decrease of soil fertility and plant productivity was found in strongly eroded soil.
  • Authors:
    • Ren, S.
    • Gao, W.
    • Yang, J.
  • Source: SOIL & TILLAGE RESEARCH
  • Volume: 151
  • Year: 2015
  • Summary: Integrating fertilizer nitrogen with organic materials was an important management strategy for sustainable agriculture production systems in most soils low in organic matter. A 33-year-old experiment with various fertilizations in a double cropping system rotated with winter wheat (Triticum aestivum L) and maize (Zea mays L) on a fluvo-aquic soil in Tianjin was evaluated. The six treatments used were control, N, NPK, NM, NS and NGM, representing various combinations of N, P, K, organic manure (M), straw (S) and green manure (GM) fertilizer applications. The specific objective of this study was to evaluate the long-term effects of combined use of organic materials and chemical fertilizer nitrogen on crop yields, soil organic carbon (SOC) and soil total nitrogen (TN).As a result, wheat and maize yields in the plot under the N treatment decreased with time, whereas the yields increased in the plot under NM treatment for both crops. The yields in NS and NGM treatments maintained a stable and higher level. Generally, both wheat and maize yields were significantly higher in NM and NPK than those in other treatments. The SOC and TN contents with all treatments showed an increasing trend with time. Compared with the N treatment, the average SOC and TN contents were 38.0 and 17.3%, 14.2 and 6.7%, and 12.9 and 6.1% larger, respectively, for NM, NPK, and NS. In addition, the SOC contents with the five treatments (N, NGM, NS, NPK and NM) increased by 25.5, 33.1, 42.1, 69.7 and 145.6%, respectively, by 2012; for TN they increased by 6.6, 17.8, 23.2, 35.5 and 57.5.5%, respectively, above the values obtained in 1979. TN contents were significantly correlated with SOC at each treatment (P<. 0.01). Soil C/N ratios were generally around 9 to 14 during cultivate time. The average soil C/N ratio in NM was significantly higher than those in other treatments, and the soil C/N ratios among the other four treatments were not significantly different.Overall, the results suggest that organic manure along with chemical N must be used to sustain the productivity and promote C and N sequestration of wheat-maize system in the fluvo-aquic soils of the Tianjin areas.
  • Authors:
    • Lal, R.
    • Pu, C.
    • Wang, M.
    • Xue, J. F.
    • Liu, S. L.
    • Yin, X. G.
    • Zhao, X.
    • Zhang, H. L.
    • Chen, F.
  • Source: CLIMATIC CHANGE
  • Volume: 129
  • Issue: 1-2
  • Year: 2015
  • Summary: Climate change has been a concern of policy makers, scientists, and farmers due to its complex nature and far-reaching impacts. It is the right time to analyze the impacts of climate change and potential adaptations, and identify future strategies for sustainable development. This study assessed changes in climatic factors (e.g., temperature and precipitation) at three typical sites (i.e., Luancheng, Feixiang, and Huanghua) in the North China Plain (NCP), and analyzed adaptations of farming practices. Results indicated that the mean annual temperature followed a significant increasing trend during 1981-2011, with 0.57, 0.47, and 0.44 A degrees C decade(-1) for Luancheng, Huanghua, and Feixiang, respectively. A significant increase of 0.67, 0.53, and 0.38 A degrees C decade(-1) was observed for the winter-wheat (Triticum aestivum L.) season for Luancheng, Huanghua, and Feixiang, respectively (P < 0.05), but no significant change for the summer-corn (Zea mays L.) season for the three sites. The annual accumulated temperature (a parts per thousand yen10 A degrees C) increased significantly during 1981-2011 (P < 0.01), with 17.60, 10.49, and 14.09 A degrees C yr(-1) for Luancheng, Huanghua, and Feixiang, respectively. There was no significant increase of mean annual precipitation, which had large inter-annual fluctuations among the three sites. In addition, significant challenges lie ahead for the NCP due to climate change, e.g., increasing food grain demand, water shortages, high inputs, high carbon (C) emissions, and decreasing profits. Trade-offs between crop production, water resource conservation, and intensive agricultural inputs will inhibit sustainable agricultural development in the NCP. Farming practices have been adapted to the climate change in the NCP, e.g. late seeding for the winter-wheat, tillage conversion, and water saving irrigation. Therefore, innovative technologies, such as climate-smart agriculture, will play important roles in balancing food security and resources use, enhancing water use efficiency, reducing C emissions in the NCP. Coordinated efforts from the government, scientists, and farmers are also necessary, in response to climate change.
  • Authors:
    • Islam, K. R.
    • Mahmood, T.
    • Bangash, N.
    • Aziz, I.
  • Source: Pakistan Journal of Botany
  • Volume: 47
  • Issue: 1
  • Year: 2015
  • Summary: There is a global concern about progressive increase in the emission of greenhouse gases especially atmosphere CO2. An increasing awareness about environmental pollution by CO2 emission has led to recognition of the need to enhance soil C sequestration through sustainable agricultural management practices. Conservation management systems such as no-till (NT) with appropriate crop rotation have been reported to increase soil organic C content by creating less disturbed environment. The present study was conducted on Vanmeter farm of The Ohio State University South Centers at Piketon Ohio, USA to estimate the effect of different tillage practices with different cropping system on soil chemical properties. Tillage treatments were comprised of conventional tillage (CT) and No-till (NT). These treatments were applied under continuous corn (CC), corn-soybean (CS) and corn-soybean-wheat-cowpea (CSW) cropping system following randomized complete block design. No-till treatment showed significant increase in total C (30%), active C (10%), and passive salt extractable (18%) and microwave extractable C (8%) and total nitrogen (15%) compared to conventional tillage practices. Total nitrogen increased significantly 23 % in NT over time. Maximum effect of no-till was observed under corn-soybean-wheat-cowpea crop rotation. These findings illustrated that no-till practice could be useful for improving soil chemical properties.
  • Authors:
    • Echeverria, H.
    • Rozas, H. S.
    • Calvo, N. I. R.
    • Diovisalvi, N.
  • Source: Agronomy Journal
  • Volume: 107
  • Issue: 2
  • Year: 2015
  • Summary: In-season N applications to spring wheat ( Triticum aestivum L.) may increase profits and improve N fertilizer accuracy. The objectives were to develop a calibration tool employing normalized difference vegetative index (NDVI) and SPAD 502 chlorophyll meter (SPAD) measurements for calculating the differential from the economic optimum N rate (dEONR) at growth stages Z22, Z24, and Z31 to Z39 and provide N rate algorithms for use in applying N fertilizer at a variable rate. Sensing was conducted trials over 3 yr encompassing 10 site-years across Southeastern Buenos Aires Province, Argentina. The relationship between sensor indices and dEONR was evaluated by fitting quadratic plateau (QP) regression models. Statistically significant QP models were determined at the Z24, Z31, and Z39 growth stages. Relative SPAD (rSPAD) and relative NDVI (rNDVI) reduced variation and improved the calibration of measured N stress with the dEONR. For Z31 and Z39, the rSPAD had the best goodness of fit statistics when compared to rNDVI [adjusted R2 (adj R2)=0.67 and 0.57 at Z31 and 0.68 and 0.52 at Z39, respectively]. However, adjustment at Z24 was higher for rNDVI (adj R2=0.53 and 0.61 for rSPAD and rNDVI, respectively). A single QP model to estimate the dEONR with 58% confidence was adjusted for the Z31 and Z39 growth stages. This indicates that the same calibration for N rate determination based on rSPAD or rNDVI values can be used during stem elongation in spring wheat. This model can be used as an N rate algorithm for applying N fertilizer in-season.
  • Authors:
    • Sheaffer, C. C.
    • Fernandez, A. L.
    • Wyse, D. L.
  • Source: Agronomy Journal
  • Volume: 107
  • Issue: 1
  • Year: 2015
  • Summary: Field pea ( Pisum sativum L.) and lentil ( Lens culinaris Medik.) have potential as grain-producing legumes in organic rotations, but their yield is limited by weed competition. Intercropping can control weeds and increase total grain productivity per land area compared to sole cropping. A field experiment was conducted to investigate the effect of intercropping on field pea and lentil yields. Intercrop treatments were spring wheat ( Triticum aestivum L.), oat ( Avena sativa L.), and radish ( Raphanus sativus L.), which were harvested for grain; and winter rye ( Secale cereale L.) and rapid-cycling brassica ( Brassica campestris L.), which were not harvested. Intercropped lentil yields and total (lentil plus intercrop) yields were lower than or equal to weeded and unweeded sole cropped lentils in 5 of 6 site-years. Intercropped pea yields and total (pea plus intercrop) yields were lower than or equal to weeded and unweeded sole cropped pea in all site-years. Unharvested intercrops showed variable effectiveness at suppressing weeds. In lentil, winter rye intercropping reduced weed biomass compared to the unweeded control in 4 site-years, and rapid-cycling brassica reduced weed biomass in 2 site-years. In pea, winter rye, and rapid-cycling brassica treatments reduced weed biomass in all site-years. However, reductions in weed biomass were not associated with increases in grain yield. Estimated net returns to intercropping were variable, but generally similar for sole crops and intercrops on average. We did not observe consistent agronomic or economic advantages to the use of intercrops with field pea and lentil in the Minnesota environments studied.
  • Authors:
    • Bu, Q.
    • Sun, Z.
    • Li, Z.
    • Lu X.
  • Source: Agronomy Journal
  • Volume: 107
  • Issue: 1
  • Year: 2015
  • Summary: Straw mulching is used widely to improve soil fertility in the black soil region of northeastern China, but there have been few evaluations of its effects on soil water content, N use by crops, and crop growth. Field experiments were conducted during two growing seasons in Jilin Province, to study the effects of straw mulching on maize yield, evapotranspiration (ET), water use efficiency (WUE), and nitrogen use efficiency (NUE) under rainfed conditions. Measurements were conducted in a treatment with maize straw mulch on the soil surface (SM) and a control treatment with no mulch (NM). The SM treatment caused a significant decline of soil temperature and increase of soil moisture in the early growing season, compared to the NM treatment. However, the use of mulching reduced maize yields by 18% in 2011 and 26% in 2012. It also decreased WUE by 16% in 2011 and 21% in 2012, and decreased NUE by 27% in 2012, though it had no effect on total ET. Therefore, the use of mulch is not recommended as an approach for improving water and N use and maize yields, in the semi-humid black soil region of northeastern China, when the water content of soil is sufficient for maize growth.
  • Authors:
    • Baruah, K. K.
    • Bhattacharya, S. S.
    • Saikia, J.
  • Source: Journal
  • Volume: 203
  • Year: 2015
  • Summary: Management of soil in agricultural ecosystem is considered to be important in maintaining soil health and soil carbon storage. Various combinations of inorganic fertilizers, FYM and crop residues were assessed in a wheat crop grown in alluvial soil for two consecutive years. We studied several attributes like soil organic carbon (SOC), soil total carbon (TC), soil carbon storage (SCS), soil moisture content (SMC), easily mineralizable N along with above ground and below ground biomass, photosynthetic rate and grain yields during various growth stages. Wheat biomass yield was increased with application of organic amendments, while carbon assimilation by plant photosynthesis during the reproductive stages enhanced with increment of SOC. We recorded about ~10.88% and 10.52% organic SCS in soil depth of 0-15 cm and about ~11.50% and 12.46% in soil depth of 15-30 cm under 100% NPK + CR + FYM and 80% NPK + CR + FYM treatments, respectively. Hence, CR and FYM in combination can maintain SOC stock considerably and 80% NPK + CR + FYM substitutes 20% inorganic fertilizer without compromising crop growth and development.
  • Authors:
    • Reibe,K.
    • Gotz,K. P.
    • Ross,C. L.
    • Doring,T. F.
    • Ellmer,F.
    • Ruess,L.
  • Source: Soil Biology & Biochemistry
  • Volume: 83
  • Year: 2015
  • Summary: The effects of biochar (maize biochar - MBC, wood biochar - WBC) and unfermented or fermented hydrochar (HTC) on the euedaphic Collembola Protaphorura fimata and on spring wheat were investigated in greenhouse experiments. The impact of char type, amount of fermented HTC, and MBC-Collembola interactions were assessed. Generally, shoot and root biomass as well as abundance of P. fimata were not affected by the different chars. However, with increasing amounts of fermented HTC the abundance of P. fimata declined, whereas shoot biomass of wheat increased. Moreover, MBC altered root morphology and resulted in thicker roots with higher volume. The latter was not apparent when Collembola were present.
  • Authors:
    • Pal, M.
    • Chakraborty, D.
    • Sehgal,V. K.
    • Saha, S.
  • Source: Agriculture Journal
  • Volume: 203
  • Year: 2015
  • Summary: Experiments on chickpea ( Cicer arietinum L.) were performed in open-top chambers during 2010-11 and 2011-12 to assess effects of atmospheric CO 2 enrichment on the quality of seeds. Although no physical modification was observed, an increase in seed water uptake was recorded in plants grown under enriched atmospheric CO 2 condition. Germination of seeds reduced by 45-47%, while seed leachate conductivity increased by 10-17%. Seedling vigor decreased, although root and shoot lengths and seedling biomass showed negligible changes. Similarly, atmospheric CO 2 enrichment reduced field emergence of seedlings with no change in root characteristics of the emerged seedlings. A decrease in protease activity supports the reduced seed viability, although no change in grain phosphatase and alpha-amylase activities were recorded. Increase in carbon content in germinating seed-cotyledon along with decrease in N in cotyledon resulted in large increase in C:N ratio for the plants grown under enriched CO 2 condition. The starch content increased with no change in soluble sugar in germinating seed-cotyledons. This indicates more carbonaceous seeds from plants grown under enriched CO 2 environment. Results suggest that rising atmospheric CO 2 might have adverse impact on viability and germination of chickpea seeds, and cause nutritional imbalance through increase in C with dilution of N contents in germinating seed-cotyledons.