Combined Application Of Chemical Fertilizers Research Articles

Carbon Mineralization and Inorganic Nitrogen Pools under Terminalia chebula Retz.-Based Agroforestry System in Himalayan Foothills, India

Abstract Soil organic matter is major terrestrial pool for soil organic carbon (C) and nitrogen (N), and their decomposition is sensitive to vegetation and climate change. Integrated nutrient management (INM) deals with the combined application of chemical fertilizers and organic manures for nutritional requirement of crops and avoid the adverse effect of long-term application of chemical fertilizer on crop production and their sustainability. The present study was carried out to investigate the influence of different nutrient sources on soil C mineralization and inorganic N pools in a Terminalia chebula Retz, based on a agroforestry system. The results showed that the highest CO2 evolution was recorded in 100 percent INM and minimum in farmyard manure treatment after 120 days of incubation. Inorganic N was higher under the agroforestry system than under the open system. Among the different nutrient sources, the highest inorganic N was recorded in a 100 percent INM nutrient source and minimal in wheat straw treatment. The yield of turmeric was higher under the T. chebula-based agroforestry system (20.87 t ha–1) than under the open system (19.27 t ha–1). Results suggest that agroforestry systems using the INM approach can enhance C mineralization and inorganic N concentration with improved crop productivity in the Himalayan foothills. Study Implications: Fertilizer has been used since ancient times, and if well managed it can be an asset, promoting sustainable agriculture and increasing crop production, particularly for smallholder farmers in the Himalayan region of India. We compared fertilizer application practices under an agroforestry system in a representative Himalayan region of India. The majority of farmers in the region of the Himalayan foothills having marginal land and they are not able to produce optimum food grains for their requirement. However, their demands are increasing day by day, so to fulfill their demand, they have to adopt agroforestry. Agroforestry may be fulfilling their demand in terms of food, fuel, fodder, and other intangible benefits. Moreover, to increase the production under agroforestry, we have to apply organic and inorganic fertilizer in the soil either as the sole application or as a combination of these fertilizers. The application of these fertilizers will improve the productivity and fertility of land, especially carbon mineralization and inorganic nitrogen. These two soil properties are important to study because these are limiting to land productivity. In addition, efforts to improve integrated nutrient management in the Himalayan region of India would strengthen farmers’ incomes by strengthening land fertility and productivity. The rapid increase in human population over the last century is putting a massive pressure on existing resources, namely soil and water, resulting in environmental degradation in some regions around the world. As productive land becomes scarce, marginalized farmers are pushed into fragile croplands and forest lands unsuitable for modern agriculture which, in turn, is vulnerable, to degradation. If the present trend in population growth persists, pasture and forest lands will be further reduced (Satterthwaite et al. 2010). At this stage, the value of growing trees becomes more significant, and participation in tree planting schemes should be encouraged. However, this option is most feasible when combined with agriculture. As a result, agroforestry is an important management strategy that not only helps to meet the world food requirements but also helps to protect soil from degradation (Ram et al. 2017) and can enhance soil organic matter levels by adding the quantity of above- and below-ground organic matter inputs to soils (Nair et al. 2009, Marone et al. 2017).

Divergent patterns of microbial community composition shift under two fertilization regimes revealed by responding species

Using patterns of belowground biodiversity to predict ecological functions and to manage productivity has been a longstanding objective for agronomists and ecologists. However, inconsistent associations between microbial diversity and fertilization have been found in frequency, which can be partly due to the dilution effect of immense silent species in microbial communities. Therefore, we studied the responding pool of the microbial communities, which was determined by filtering out taxa that did not vary significantly between fertilization treatments and the control. With responding species, we hypothesized that the difference of microbial response to different fertilization regimes and between bacterial and fungal response to treatments can be enlarged. In this study, bacterial and fungal community compositions and networks were characterized from soils with chemical fertilization (F), the combined application of chemical fertilizers and organic residues (MRF) and without fertilization (Control) in a 7-year experiment located at the Fengqiu Agroecological Experimental Station. As a result, >90% of the phyla, 75% of the genera and 92% of the OTUs were silent microbes. When filtering out these species, 9 phyla, 88 genera and 185 OTUs of bacteria responded significantly to the MRF treatment compared with those of the Control with an average abundance variation of 0.06% in responding OTUs. In contrast, only 2 phyla, 9 genera and 30 OTUs of bacteria significantly responded to the F treatment with an average amplitude of 0.11%. The higher connectedness and the lower average geodesic distance under the MRF treatment showed a more connective and closer bacterial network compared with the F treatment. Similar but stronger responses were detected in the fungal community composition and networks. To conclude, combined fertilization exerted a moderate impact on many microbial taxa (MM pattern), and chemical fertilization showed a substantial effect on a small amount of taxa (SS pattern). It was further inferred that a variation of the “MM” pattern can result in a more stable, harmonious and efficient ecosystem via maintenance of microbial diversity, stimulation of beneficial species, and exhibition of a more efficient microbial network. Our study showed explicit patterns of microbial communities under fertilization regimes revealed by responding species and highlighted the advantages of combined fertilization with organic matter in agroecosystems.

Quantifying soil N pools and N2O emissions after application of chemical fertilizer and straw to a typical chernozem soil

An incubation experiment with equivalent N rates was conducted for 56 days using a typical black soil amended with chemical fertilizer with or without straw amendment using a 15N cross-labeling technique. Compared with the chemical fertilizer treatment (15NCF), chemical fertilizer combined with straw treatment (CF + S) showed a significantly higher (P < 0.05) contribution from applied N to microbial biomass N (BN) in the first 14 days and to particulate organic N (PON) and mineral-associated total N (MON) throughout the incubation. Straw application in the CF + S treatment significantly (P < 0.05) decreased the recovery of chemical fertilizer N as soil inorganic N except at day 3 but increased the recovery of chemical fertilizer N as BN before day 14 and as PON and MON from day 14 to the end of the incubation period. At the end of the incubation period, the total N2O-N emissions in the CF + S treatment increased significantly (P < 0.05) compared with the CF treatment, and the increase in N2O-N emissions was 73% from chemical fertilizer and 27% from straw N individually. Our results suggest that the combined application of chemical fertilizer and straw increased soil fertility together with an increase in N2O emissions in the typical black soil and the N2O emissions from straw cannot be ignored.

Effects of different manure nitrogen input ratio on rhizosphere soil microbial biomass carbon, nitrogen and microbial quotient in double-cropping rice field

To explore the characteristics of rhizosphere soil microorganisms in paddy fields with different manure nitrogen (N) input ratios at different growth stages of early and late rice in double-cropping rice system, a field experiment was conducted with five different treatments: 1) 100% N of chemical fertilizer (M1), 2) 30% N of organic matter and 70% N of chemical fertilizer (M2), 3) 50% N of organic matter and 50% N of chemical fertilizer (M3), 4) 100% N of organic matter (M4), and 5) no N fertilizer input as a control (M0). The rhizosphere soil microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), and microbial quotient (SQ) of the paddy fields were measured using the fumigation-extraction and chemical analysis methods. The results showed that the rhizosphere MBC, MBN, and SQ of the paddy fields at main different growth stages of early and late rice were increased by fertilization, which increased first and then decreased with the development of rice growth period, peaked at the heading stage, and reached the minimum value at the maturity stage. The effects of different fertilization treatments were in order of M4＞M3＞M2＞M1＞M0, with no significant difference among M2, M3 and M4, but being significantly higher than M0. Therefore, the application of organic matter, and combined application of chemical fertilizer with organic matter could significantly increase the rhizosphere MBC, MBN, and SQ of the paddy fields at early and late rice growth period, while chemical fertilizer alone had little effect.

Dynamics of maize straw–derived nitrogen in soil aggregates as affected by fertilization

The addition of maize residue nitrogen (N) to the soil strongly influences soil N accumulations, but the specific contributions of maize residue N to soil aggregates based on long-term fertilization remain largely unknown. This study involved a 360-day laboratory incubation experiment to determine the dynamics of N derived from maize straw in Mollisol soil aggregates applying different long-term fertilization treatments. In 2015, three soil samples from different fertilizers treatments were collected from the upper layer of soil (0–20 cm) of the field at a long-term Mollisol (Luvic Phaeozem) experimental site established in 1980 in Gongzhuling, Jilin Province, China. The fertilizer treatments included no fertilizer (CK); a combination of nitrogen, phosphorous and potassium fertilizers (NPK); and NPK combined with manure (MNPK). Three treatments of soils were incubated for 360 days at 25 °C, with or without 15N-labeled maize straw and destructively collected on days 45, 90, 135, 180 and 360. Soil samplings were separated into two aggregate fractions (macroaggregates, ≥ 0.25 mm; microaggregates, NPK > CK after 360 days of incubation. The results revealed that the combined application of chemical fertilizer and organic manure had higher capacity to retain maize straw–derived N, and more of it was retained in macroaggregates in the beginning. The addition of straw residue accelerated the formation of macroaggregates in the soils with lower C/N ratios.

Temporal Dynamics of Nitrous Oxide Emission and Nitrate Leaching in Renovated Grassland with Repeated Application of Manure and/or Chemical Fertilizer

Managed grassland is occasionally renovated to maintain plant productivity by killing old vegetation, ploughing, and reseeding. This study aimed to investigate the combined effect of grassland renovation and long-term manure application on the temporal dynamics of nitrous oxide (N2O) emission and nitrate nitrogen (NO3−–N) leaching. The study was conducted from September 2013 to September 2016 in a managed grassland renovated in September 2013. In this grassland, two treatments were managed—chemical fertilizer application (F treatment) and the combined application of chemical fertilizer and beef cattle manure (MF treatment)—for eight years before the renovation. The control treatment without fertilization (CT) was newly established in the F treatment. The soil N2O flux was measured using a closed chamber method. A leachate sample was collected using a tension-free lysimeter that was installed at the bottom of the Ap horizon (25 cm deep), and total NO3−–N leaching was calculated from leachate NO3−–N concentration and drainage volume was estimated by the water balance method. In the first year after renovation, the absence of plant nitrogen uptake triggered NO3−–N leaching following rainfall during renovation and increased drainage water after thawing. NO3−–N movement from topsoil to deeper soil enhanced N2O production and emission from the soil. N2O emission in MF treatment was 1.6–2.0 times larger than those of CT and F treatments, and NO3−–N leaching in MF treatment was 2.3–2.6 times larger than those of CT and F treatments in the first year. Mineral nitrogen release derived from long-term manure application increased NO3−–N leaching and N2O emission. In the second year, N2O emission and NO3−–N leaching significantly decreased from the first year because of increased plant N uptake and decreased mineral nitrogen surplus, and no significant differences in N2O emission and NO3−–N leaching were observed among the treatments. In the second and third years, NO3−–N leaching was regulated by plant nitrogen uptake. There were no significant differences in NO3−–N leaching among the treatments, but N2O emission in MF treatment was significantly smaller than in the F treatment. Long-term manure application could be a possible option to mitigate N2O emission in permanent grassland; however, the risk of increased NO3−–N leaching and N2O emission in the renovation year induced by manure nitrogen release should be noted.

Relationship of crop yield and soil organic carbon and nitrogen under long term fertilization in black loessial soil region on the Loess Plateau in China.

The feedbacks between crop yield and soil organic carbon and total nitrogen contents were examined in a long-term experiment, which was established on black loessial soil on the Loess Pla-teau in China. There were six treatments, including CK (no fertilizer), N (single nitrogen fertilizer), NP (chemical fertilizers NP), SNP (straw and chemical fertilizers NP), M (organic manure) and MNP (organic manure and chemical fertilizers NP). Results showed that balanced application of chemical fertilizers, single application of organic manure, the combined application of chemical fertilizers with organic manure and chemical fertilizers coupled with straw returning to the field all significantly increased crop yield and its stability compared with control (CK). The yields of maize and wheat in NP, SNP, M and MNP treatments increased by 92%, 97%, 93%, 141% and 147%, 164%, 139%, 214%, respectively, compared with the control. The annual mean yields of maize and wheat in NP treatment were equal to or higher than those of the local conventional fertilization practices and quite stable among different years, which indicated that the fertilization rates with N 90 kg·hm-2 and P2O5 75 kg·hm-2 were enough for crop growth in wheat-maize rotation system. Application of chemical fertilizer P every other year combined with straw returning to the field (SNP) had similar crop yield values with NP treatment, with the P application amount could be reduced by 50%. The balanced application of chemical fertilizers, organic manure application, the combined application of chemical fertilizers with organic manure, and chemical fertilizers coupled with straw returning to the field could significantly increase soil organic carbon content, whereas chemical fertilizer application had no significant influence on soil total nitrogen content. Across all treatments, the contents of soil organic carbon and total nitrogen were significantly and positively correlated. Under different fertilization treatments, organic carbon sequestration rate was between 15% and 41%. In SNP treatment, the soil organic carbon content enhanced 0.06 g·kg-1 when the amount of organic carbon input every increased 1 t·hm-2, while in CK, N, NP, M and MNP treatments, the increments was between 0.12 and 0.15 g·kg-1. The yields of both maize and wheat were positively correlated with soil total nitrogen content. Maize yield constantly increased with the increases of soil organic carbon content, but wheat yield increased at first and then kept stable with the increases of soil organic carbon content, with a threshold of 6.8 g·kg-1. In conclusion, long-term balanced application of chemical fertilizers, organic manure application, chemical fertilizers combined with manure and chemical fertilizers coupled with straw returning to the field could significantly increase soil organic carbon and total nitrogen contents, consequently resulted in higher crop yield and stubble amount returned to soil, the increase of stubble returned to soil further led to the increase of soil organic carbon and total nitrogen contents, which formed the mutual promotion feedback relationship each other in the black loessial soil region of Loess Plateau in China.

Distribution of agricultural pesticides in the freshwater environment of the Guayas river basin (Ecuador)

The rapid increase and transition to more intensive agricultural activities in developing nations are often leading to misuse and overuse of pesticides, making their environment vulnerable for pesticide accumulation. In the present study, the Guayas river basin was taken as a representative case study to evaluate pesticide contamination of the Ecuadorean freshwater environment. Pesticide contamination was determined at 181 sampling sites by a multi-residue method using solid phase extraction (SPE) and pesticide residues were linked with agricultural land use activities to identify the main pollution sources. Moreover, the biological water quality status based on macroinvertebrate communities was determined at every location and the relation with the occurrence of pesticide residues was further investigated. Results showed that pesticide contamination of the freshwater environment was widely present in the Guayas river basin with detections at 108 sampling sites (60%). A total of 26 pesticide products were identified. Most frequently detected pesticides included cadusafos (62 locations), butachlor (21 locations) and pendimethalin (21 locations), with concentrations up to 0.081, 2.006 and 0.557 μg·L−1 respectively. Pesticide residues detected in this study did not significantly influence the biological water quality (p = 0.69), but were observed to be positively correlated with ammonium concentrations, supporting the assumed combined application of chemical fertilizers and pesticides in agriculture. These pesticide residues were also associated with one or more agricultural crops, with in particular the banana and rice industries identified as major pollution sources. Both high consumption rates and non-specific application methods, such as aerial spraying of banana plantations and application directly into the water layer of irrigated rice fields, may attribute to pesticide contamination of the freshwater environment of the Guayas river basin. It is therefore suggested that measures, e.g. legal regulations and awareness campaigns, taken to prevent environmental pollution and accumulation of pesticides primarily focus on these industries.

Effect of chemical fertilizers and biofertilizers on rajmash (Phaseolus vulgaris) in cold desert region of North-western Himalayas

A field experiment was conducted to study the combined effect of chemical fertilizers and biofertilizers on growth, yield and economics of rajmash (Phaseolus vulgaris L.) at Highland Agricultural Research and Extension Centre, Kukumseri during two consecutive summer seasons of 2012 and 2013. The experiment was laid out in randomized block design with nine treatments and replicated thrice. Growth, yield attributes and yield were significantly increased with combined application of chemical fertilizers and biofertilizers. The tallest plants were recorded in T6 (N60 P60 K30 + seed inoculated with Rhizobium and phosphate solubilizing bacteria) while the shortest plants were in T9(N0 P0 K0 BF0 ). Significantly higher values of pod length, seeds per pod, seed index, seed yield and straw yield were also recorded in T6 . Maximum mean value of dry matter efficiency and harvest index was observed in T7 (N0 P60 K30 + seed inoculated with Rhizobium and PSB) while maximum mean value of unit area efficiency, net returns and B:C ratio was in T. Based on the mean value of two years, T6 resulted in 81.11, 77.48, 77.49, 172.05 and 65.32% higher dry matter production, unit area efficiency, seed yield, net returns and B:C ratio, respectively as compared to control treatment (T9 ). Maximum mean profitability (Rupees1477/ha/day) was also recorded in T6 . Integrated application of 60 kg N, 60 kg P2 O5 and 30 kg K2 O/ha along with seed inoculation with Rhizobium and PSB proved to be the best treatment for higher productivity and profitability of rajmash crop in cold desert region of North-western Himalayas.

Effects of combined application of chemical fertilizer and vermicompost on soil fertility, leaf yield and stevioside content of stevia

Sustainable nutrient management with the combination of organic and chemical fertilizer amendment expects a key part in upgrading stevia yield without harming the environment and to build up the nutrient balance with increasing soil fertility. A pot experiment was conducted in the net house of the Department of Agricultural Chemistry, Bangladesh Agricultural University, Mymensingh to study the combined effect of vermicompost (VC) and chemical fertilizer (CF) on the growth, leaf biomass yield and stevioside content of stevia in acid soil. Six combinations of VC and CF were applied following completely randomized design (CRD) with three replications. Results showed that VC along with different rates of CF exerted significant influence on the growth, leaf biomass yield and stevioside content of stevia and postharvest soil fertility. The highest values for most of the parameters were found from the plant receiving VC @ 7.5 t ha­−1 along with 50% CF. About 578% higher leaf biomass yield was obtained from the treatment VC7.5+CF50 over control. Stevioside content was increased with the increasing levels of VC up to 7.5 t ha−1 along with 75% of CF and also with the advancement of growth period from 30 to 60 days after planting. The highest amount of stevioside (11.05%) was detected in the leaves of plant of the same treatment at harvest. Soil acidity was significantly decreased with the increased levels of VC and CF where as soil fertility in terms of organic matter and nutrient content was increased. Considering the overall performance, farmers may be advised to cultivate stevia in acid soil applying VC @ 7.5 t ha−1 along with 50% chemical fertilizer to boost up stevia production under the agroclimatic condition of the study area in the context of BangladeshJ. Bangladesh Agril. Univ. 16(1): 73-81, April 2018

Effects of combined application of chemical fertilizer and organic manure on wheat yield and leaching of residual nitrate-N in dryland soil

The effects of optimum nitrogen (N) fertilization rate with and without adding manure on wheat yield and leaching of residual nitrate-N in soil profile were examined in Weibei dryland, Shaanxi with a field experiment combined different N fertilization rates (0, 75, 150, 225, 300 kg N·hm-2) and organic manure (0 and 30 t·hm-2). The results showed that, compared to chemical N fertilizer, combined application of inorganic fertilizer and organic manure increased winter wheat yield by 14.7% when N fertilization rate was reduced by 27.1%. The highest yield was obtained when 150 kg·hm-2 of N rate was combined with the manure (N150+M). The combination of N fertilizer and manure promoted N uptake of wheat grain and increased N use efficiency by 20.2%. The highest N use efficiency was recorded in the N150+M treatment. In addition, the lea-ching of residual nitrate-N during the wheat growing season and the leaching of nitrate-N during summer fallow were decreased. When N application rate was lower than 115 kg·hm-2, N fertilizer combined with organic manure reduced the amount of nitrate-N leaching in summer fallow. We recommend the combined application of organic manure with about 150 kg·hm-2 of N fertilizers in Weibei dryland to guarantee high winter wheat yield, N use efficiency, and reduce excessive residue of fertilizer N in the soil.

Effect of integrated nutrient management on nutrient uptake and sustainable grain yield in transplanted aman rice

A field experiment was carried out at Sher-e-Bangla Agricultural University (SAU) Farm during July to November 2011 to evaluate the effect of integrated nutrient management (INM) on T. Aman rice (cv. BRRI dhan40). The field belongs to Red Brown Terrace soil under Tejgoan series having silt loam texture and 6.0 pH. Application of 70 % NPKS fertilizers + 4 t ha-1 dhaincha (Sesbania rostrata) (T1) produced the highest grain yield (5.90 t ha-1), the second highest yield (5.85 t ha-1) was obtained from 80% NPKS + 2 t ha-1 dhaincha (T2) treatment. The grain yield increased by 31.2 to 86.3% over control depending on the treatments. Treatments T1 and T2 resulted in higher N, P, K and S uptake by rice. The N, P, K and S concentrations of rice grain was higher for the treatments where Sesbania and cow dung were together applied in combination with NPKS fertilizers. The combined application of chemical fertilizers and organic manure increased organic carbon (OC), total N, available P, K and S contents in post-harvest soil. The overall results indicate that the integrated use of chemical fertilizer and organic manure can help increase grain yield of rice without deteriorating soil fertility.SAARC J. Agri., 15(1): 43-53 (2017)

Evident variations of fungal and actinobacterial cellulolytic communities associated with different humified particle-size fractions in a long-term fertilizer experiment

Cellulose is the dominant form of carbon (C) existing in arable soils, however the ecology of its degradation in soil is still relatively poorly understood. Here, community abundance and composition of fungal and actinobacterial cellulolytic genes (cbhI and GH48) from glycoside hydrolase family 7 and 48 together with characterization of fulvic acid (FA) and humic acid (HA) determined by cross polarization magic angle spinning (CPMAS) 13C nuclear magnetic resonance (NMR) spectroscopy were explored in five soil particle-size fractions (large macroaggregate, coarse sand, fine sand, silt and clay), collected from a 33-yr mineral and organic fertilizer experiment. The results revealed the significant effects of particle-size fraction and fertilization on the distribution of soil humus and cellulolytic microbial community abundance. Strong correlations were detected between C content and structure of soil humus with cellulolytic microbial abundance. Generally, larger fractions (>63 μm) especially fine sand, which showed a lower degree of humification with higher aromaticity, lower HA/FA ratio, aliphaticity and alkyl/O-alkyl ratio of HA, were associated with greater abundance of cellulolytic microbes. However, smaller fractions (<63 μm), especially the clay fraction, showed lower cbhI and GH48 gene abundances with a greater degree of humification indicated by 13C NMR spectra. Phylogenetic analysis of the obtained nucleotide sequences revealed undiscovered sequences of both fungal and actinobacterial cellulolytic microbes. However, no clear clustering of sequences from particular particle-size fraction or fertilizer treatment was observed, even though combined application of chemical fertilizer and manure significantly increased cellulolytic gene abundances.

Effects of fertilizing regime and planting age on soil calcium decline in Luochuan apple orchards

This study was conducted to assess the effects of fertilizing regime and orchard planting age on soil calcium contents and stocks in the apple orchards on the Loess Plateau. The apple orchards in Luochuan County, one of the best regions for apple plantation in the world, were selec-ted in this study. The contents of calcium carbonate,water-soluble calcium and exchangeable cal-cium at 0-100 cm soil layer under different fertilizing regimes and various planting ages were mea-sured, their stocks were calculated and their variation features were analyzed. The results showed that soil in the apple orchards in the study region was characterized by the decline in calcium contents. The decline was more serious in apple orchards with long-term application of chemical fertili-zer than in those with combined application of chemical fertilizer and farmyard manure. The average contents of calcium carbonate, water-soluble calcium and exchangeable calcium at 0-100 cm soil layer in apple orchards with long-term application of chemical fertilizer decreased by 38.8%, 25.4% and 5.6% respectively than those in the apple orchards with long-term application of both chemical fertilizer and farmyard manure. The stocks of calcium carbonate, water-soluble calcium and exchangeable calcium decreased by 36.4%, 26.0% and 4.3%, respectively. The decline of soil cal-cium was aggravated with the increase of orchard planting age. The contents of calcium carbonate, water-soluble calcium and exchangeable calcium at 0-100 cm soil layer in orchards of more than 25 years of planting age decreased by 48.8%, 69.4% and 39.5% respectively, compared with orchards of less than 10 years of planting age, and the stocks decreased by 40.8%, 64.1% and 33.0%, respectively. These results indicated that either long-term application of chemical fertilizer or long-term plantation of apple trees obviously depleted soil calcium carbonate, water-soluble calcium and exchangeable calcium. Therefore, it was recommended that application of chemical fertilizer and farmyard manure should be combined to mitigate soil calcium decline, and calcium management should be strengthened in apple orchards of more than 25 years of planting age. The fertilizing regime was a driving factor of soil calcium decline which had a significant temporal (orchard planting age) and spatial (soil depth) effect.

Chemical fertilizers could be completely replaced by manure to maintain high maize yield and soil organic carbon (SOC) when SOC reaches a threshold in the Northeast China Plain

The combined use of chemical and organic fertilizers is considered a good method to sustain high crop yield and enhance soil organic carbon (SOC), but it is still unclear when and to what extent chemical fertilizers could be replaced by organic fertilizers. We selected a long-term soil fertility experiment in Gongzhuling, Northeast China Plain to examine the temporal dynamics of crop yield and SOC in response to chemical nitrogen, phosphorus, and potassium (NPK) fertilizers and manure, applied both individually and in combination, over the course of three decades (1980–2010). We aimed to test 1) which fertilizer application is the best for increasing both maize yield and SOC in this region, and 2) whether chemical fertilizers can be replaced by manure to maintain high maize yield and enhance SOC, and if so, when this replacement should be implemented. We observed that NPK fertilizers induced a considerable increase in maize yield in the first 12 years after the initiation of the experiment, but manure addition did not. In the following years, the addition of both NPK fertilizers and manure led to an increase in maize yield. SOC increased considerably in treatments with manure but remained the same or even declined with NPK treatments. The increase in maize yield induced by NPK fertilizers alone declined greatly with increasing SOC, whereas the combination of NPK and manure resulted in high maize yield and a remarkable improvement in SOC stock. Based on these results we suggested that NPK fertilizers could be at least partially replaced by manure to sustain high maize yield after SOC stock has reached 41.96 Mg C ha−1 in the Northeast China Plain and highly recommend the combined application of chemical fertilizers and manure (i.e., 60 Mg ha−1).

长期施肥对双季稻田土壤微生物学特性的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 长期施肥对双季稻田土壤微生物学特性的影响 DOI: 10.5846/stxb201504080708 作者: 作者单位: 湖南生物机电职业技术学院,湖南省土壤肥料研究所,湖南省土壤肥料研究所,湖南省土壤肥料研究所,湖南省土壤肥料研究所,湖南省土壤肥料研究所 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金资助项目（31201178，31571591）；湖湘青年科技创新创业平台资助项目 Effects of different long-term fertilization regimes on the soil microbiological properties of a paddy field Author: Affiliation: College of Biological and Electromechanical Polytechnic,Hunan Soil and Fertilizer Institute,,,, Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:为探明不同施肥处理对早稻和晚稻各个生育时期稻田土壤微生物生物量碳、氮和微生物熵的影响，以湖南宁乡长期定位试验为平台，应用氯仿熏蒸-K2SO4提取法和化学分析法系统分析了定位长达29年5种施肥处理之间（化肥、秸秆还田+化肥、30%有机肥+70%化肥、60%有机肥+40%化肥和无肥）双季稻田土壤微生物生物量碳、氮和微生物熵的差异。结果表明，早稻和晚稻各主要生育时期，长期施肥均能提高土壤微生物生物量碳、氮含量和微生物熵，各施肥处理土壤微生物生物量碳、氮含量和微生物熵均随水稻生育期推进呈先增加后降低的变化趋势，均于齐穗期达到最大值，成熟期达到最低值；其中，以60%有机肥和30%有机肥处理双季稻田土壤微生物生物量碳、氮含量和微生物熵均为最高，均显著高于其他处理，其大小顺序表现为60%有机肥 > 30%有机肥 > 秸秆还田 > 化肥 > 无肥。长期有机无机配施可以提高土壤微生物生物量碳、氮和微生物熵，有机肥与化肥配施对提高土壤肥力效果最好。土壤微生物生物量碳、氮及微生物熵可以反映土壤质量的变化，可作为评价土壤肥力的生物学指标。 Abstract:Fertilization regimes affect the soil microbiological properties of paddy fields. In China, few studies have investigated the influence of long-term fertilizer and combined organic matter and fertilizer application on the soil's microbiological properties. Our objective was to explore the characteristics of soil microbial biomass carbon (SMBC), soil microbial biomass nitrogen (SMBN), and the soil microbial quotient of a paddy field during the early and late rice growth periods under different long-term fertilization regimes in a double cropping rice system. A long-term experiment was established in 1986 in Ningxiang county of Hunan Province, China, and five different fertilizer treatments were applied:(1) no fertilizer input (CK), (2) mineral fertilizer alone (MF), (3) rice residue plus mineral fertilizer (RF), (4) 30% organic matter and 70% mineral fertilizer (OM1), and (5) 60% organic matter and 40% mineral fertilizer (OM2). We analyzed the SMBC, SMBN, and soil microbial quotient of the fields with the above five treatments using the fumigation-extraction and chemical analysis methods. The results showed that after 29 years, the different fertilization regimes significantly affected the soil's chemical and microbial properties. Compared to the CK, the organic matter, total N, and available N, P, and K increased due to the combined application of chemical fertilizer, recycled rice straw, and chicken manure. In paddy fields, the SMBC activity, SMBN, and soil microbial quotient were increased by long-term fertilization regimes wherein applications were carried out during the early and late rice growth periods. Meanwhile, the SMBC activity, SMBN, and soil microbial quotient increased with the development of early and late rice, peaking at the heading stages of early and late rice. These measurements then reached their minimum value at the mature stages of early and late rice. Compared to the CK, the SMBN activity increased by 7.67%, 10.98%, 19.17%, and 21.75% when treated with MF, RF, OM1, or OM2, respectively, at the heading stage of early rice, and increased by 7.27%, 10.41%, 18.18%, and 20.14% when treated with MF, RF, OM1, or OM2 at the heading stage of late rice, respectively. Furthermore, the SMBC activity, SMBN, and the soil microbial quotient were significantly higher when treated with OM1 or OM2 than that in the MF, RF, or CK treatments at the different main growth stages of early and late rice, respectively. In addition, the SMBC activity, SMBN, and soil microbial quotient under different fertilization regimes were ordered as follows:OM2 > OM1 > RF > MF > CK at the main growth stages of early and late rice. The soil fertility was increased by the combined application of mineral fertilizer and organic matter, and the SMBC activity, SMBN, and soil microbial quotient were correlated with combined long-term fertilizer and organic matter application. Therefore, the combined application of chemical fertilizer and recycled rice straw or chicken manure could significantly increase the SMBC activity, SMBN, and soil microbial quotient of paddy fields during early and late rice growth. In addition, the soil microbial properties reflect changes in soil quality, such as the SMBC activity, SMBN, and soil microbial quotient, all of which can be used as biological indicators for the evaluation of soil fertility. 参考文献 相似文献 引证文献

Gross nitrogen transformations in black soil under different land uses and management systems

In this study, the 15N isotope pool dilution technique was used to investigate the gross N transformation rates in black cropland soils that had been subjected to different fertilization treatments [no fertilizer application (NF), N and P applications (NP), and N and P applications with composted pig manure (NPM)] compared to a neighboring grassland soil in northeast China. The results showed that gross N mineralization and immobilization rates were significantly higher in grassland soils than in cropland soils, whereas the reverse was true for gross nitrification rates, which led to a higher gross nitrification rate/ammonium immobilization rate in cropland soils compared to grassland soils. Long-term applications of chemical fertilizer increased the gross rates of mineralization, immobilization, and nitrification compared to the no fertilizer treatment, and this effect was more prominent when combined with application of organic manure. However, the ratio of gross nitrification rate to ammonium immobilization rate in the NPM treatment decreased compared to the NP and NF treatments, which suggested that converting grassland to cropland reduced the potential release and conservation of N and promoted N loss via NO3− leaching, whereas appropriate management practices, such as the combined application of chemical fertilizer and pig manure, could increase N retention and decrease the production and leaching of NO3−.

Sustainable banana (Musa spp) production through integrated plant nutrition system - A review

Nutrient depletion is a reversible constraint and therefore high agricultural production can be realized with appropriate soil nutrient management. Careful manipulation of nutrient stocks and flows, in order to achieve satisfactory and sustainable level of agricultural production is the Integrated Plant Nutrient System (IPNS). IPNS is holistic and sustainable approach to attain the maximum profitability and cost benefit ratio for the farmers. It is nutrient saving, controls erosion and recycles crop residues, manures and other biomass or nutrient adding. Different IPNS packages have been reported to improve growth and yield of banana (Musa spp). Through combined application of chemical fertilizers, organic manures, bio-fertilizers and bio-control agents in IPNS have profound effect in improving quality parameters like total soluble solids (TSS), ascorbic acid, total reducing and non-reducing sugars of banana. It also improves the physical, chemical and biological properties of soil, especially the number of beneficial soil microflora. Considering the ill effects of chemical fertilizers, it is high time to use IPNS in banana cultivation instead of using chemical fertilizers alone. The paper reviews all the literature on various aspects of banana cultivation from the IPNS perspective for better understanding and future strategies for improved production as well as quality of banana.

Crop Yield Response to Soil Organic Carbon Stock over Long-Term Fertilizer Management in Huang-Huai-Hai Plains of China

Huang-Huai-Hai (HHH) plains of China account for 69.2 % of annual wheat (Triticum aestivum) and 35.3 % of annual maize (Zea mays) production in China, and are China’s principal crop production area. Thus, the understanding of crop yield response to increase in soil organic carbon (SOC) stock in different fertilizer managements, soil types, and the threshold of SOC stock in the HHH region is the key factor affecting the adoption of fertilizer managements. Thus, data from ten long-term experiments have been collated and synthesized in this article. These long-term experiments involved four groups of similar fertilizer managements: (i) no chemical fertilizer or organic as control (CK), (ii) chemical nitrogen (N) fertilizer applied without organic manure (UF), (iii) combined application of chemical fertilizer (N, P, K) without organic manure (CF), and (iv) integrated nutrient management (INM) based on use of manure/straw and chemical fertilizer (N, P, K). The results indicated that (i) Crop yield increased with increase in SOC stock in all sites across the HHH. Increase in SOC stock by one Mg ha−1 increased crop yield (kg ha−1 year−1) from 66.9 in Changpin to 333.2 in XinjiA and 495.2 in XinjiB in sub-region 1, 1,031.4 in HengshuiA, 419.2 in HengshuiB, and 148.5 in Yucheng in sub-region 2, and 914.2 in ZhengzhouA, 1,116.6 in ZhengzhouB, 1,135.6 in Xuzhou, and 437.3 in Mengcheng in sub-region 3. (ii) The magnitude of increase in crop yield with increase in SOC stock varied among CK,UF,CF, and INM treatments for different sites across the HHH. A gradual but sustainable increase was observed through SOC-induced improvements in soil quality. (iii) The threshold value of SOC stock for sub-region 1 was 44.9 Mg ha−1 in XinjiA with the corresponding crop yield of 12.3 Mg ha−1 year−1. The available data were not sufficient to identify the threshold level of SOC stock for sub-region 2. The threshold values of SOC stock(Mg ha−1) for sub-region 3 were 27.5 in Xuzhou, and 44.6 in Mengcheng with the corresponding crop yield(Mg ha−1 year−1) of 14.5 and 10.5, respectively. (v)The threshold value of SOC stock in response to crop yield for the entire HHH ranged from 25.0 to 41.0 Mg ha−1, and the corresponding potential of increase in crop yield from 12.8 to 18.0 Mg ha−1 year−1. In comparison with a rapid yield response by application of chemical fertilizers, increase in SOC stock and improvement in soil quality result in a gradual but sustainable yield increase. Thus, restoration of the depleted SOC stock by conversion to a restorative land use and adoption of INM across the HHH can enhance soil quality and improve crop production.

Amelioration of Sodic Soil for Wheat Cultivation Using Bioaugmented Organic Soil Amendment

AbstractA novel bioaugmented organic amendment (SFOA) [consisted of vermicompost (pre‐enriched with plant growth promoting fungi) mixed with pressmud and Azadirachta indica (A. Juss.) seed cake] was developed to reclaim sodic soil and support wheat production. A field trial of the SFOA application with/without chemical fertilizers conducted in completely randomized design with four replications to compare growth, yield and seed protein contents of wheat (Triticum aestivum L.) on sodic soil. The favourable changes occurred in different properties of amended soils were studied. A combined application of chemical fertilizer and SFOA significantly (p &lt; 0·05) increased the number of spikelet per plant (63%) and weight of grains per ear (65%) in the amended soil compared with the control. Likewise, the grain yield, weight of 1000 grains and seed protein contents of wheat were significantly (p &lt; 0·05) increased in the combined application compared with other treatments. The expression of protein bands with molecular weights of 36, 52 and 66 kDa were higher in seeds of wheat under the combined treatment. The improvement in wheat production was attributed to significant favourable changes in different soil characteristics such as bulk density, total organic C, alkaline phosphatase, β‐glucosidase, dehydrogenase and cellulase activities that were increased by 234%, 181%, 234%, 176%, 189% and 150%, respectively, in case of amended soil under the combined treatment compared with the control. The tested SFOA may be recommended as soil amendment for reclaiming sodic soil and supporting wheat cultivation with better crop growth and yield in combination with chemical fertilizers on sodic soil. Copyright © 2014 John Wiley &amp; Sons, Ltd.