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1.
This study addressed if long-term combined application of organic manure and inorganic fertilizers could improve the synchrony between nitrogen (N) supply and crop demand. 15?N-labeled urea was applied to micro-plots within three different fertilized treatments (no fertilizer, No-F soil; inorganic NPK fertilizers, NPK soil; and manure plus inorganic NPK fertilizers, MNPK soil) of a long-term field trial (1990–2009) in a dryland wheat field in the south Loess Plateau, China. After one season of wheat harvest, 15?N use efficiency was 20, 58, and 65 % in the No-F, NPK, and MNPK soil, respectively. During the early wheat growth stage, microbial immobilization of applied 15?N was significantly (P?<?0.05) highest in the MNPK soil (15.3 %), higher in the NPK soil (12.6 %), and lowest in the No-F soil (7.4 %). Of the 15?N immobilized by the soil microbial biomass, 69 % (NPK soil) to 83 % (MNPK soil) was released between the stem elongation and flowering of wheat. Compared with the NPK soil, the MNPK soil had significantly (P?<?0.05) higher grain yield. Our findings highlight that long-term application of organic manure with inorganic fertilizers cannot only improve the synchrony of N supply for crop demand but also increase N use efficiency and grain yield.  相似文献   

2.
Summary Azolla spp. and Sesbania spp. can be used as green manure crops for wetland rice. A long-term experiment was started in 1985 to determine the effects of organic and urea fertilizers on wetland rice yields and soil fertility. Results of 10 rice croppings are reported. Azolla sp. was grown for 1 month and then incorporated before transplanting the rice and 3–4 weeks after transplanting the rice. Sesbania rostrata was grown for 7–9 weeks and incorporated only before transplanting the rice. Sesbania sp. grew more poorly before dry season rice than before wet season rice. Aeschynomene afraspera, which was used in one dry season rice trial, produced a larger biomass than the Sesbania sp. The quantity of N produced by the Azolla sp. ranged from 70 to 110 kg N ha-1. The Sesbania sp. produced 55–90 kg N ha-1 in 46–62 days. Rice grain yield increases in response to the green manure were 1.8–3.9 t ha-1, similar to or higher than that obtained in response to the application of 60 kg N ha-1 as urea. Grain production per unit weight of absorbed N was lower in the green manure treatments than in the urea treatment. Without N fertilizer, N uptake by rice decreased as the number of rice crops increased. For similar N recoveries, Sesbania sp. required a lower N concentration than the Azolla sp. did. Continuous application of the green manure increased the organic N content in soil on a dry weight basis, but not on a area basis, because the application of green manure decreased soil bulk density. Residual effects in the grain yield and N uptake of rice after nine rice crops were found with a continuous application of green manure but not urea.  相似文献   

3.
Organic-N fertilizers in the form of flood-tolerant, leguminous, stem-nodulating Sesbania rostrata and Aeschynomene afraspera may be useful alternatives to resource-poor rice farmers if applied as green manure. Therefore, the accumulation of N by these green manure species and their effect on the performance and yield of wetland rice (IR 64) was examined at four different sites in Luzon, Philippines. Soils deficient in N, P, and K were selected and compared with the fertile Maahas clay of the International Rice Research Institute (IRRI) at Los Baños. The green manure plants were grown under flooded conditions for 49 days in the wet season of 1987, chopped, and then ploughed in before transplanting rice seedlings. In a second experiment, the effect of S. rostrata green manure was studied under rainfed conditions. All green manure treatments were compared to an urea treatment (60 kg N ha–1) and an untreated control. Both legumes developed well, even on the marginally productive soils. S. rostrata accumulated up to 190 kg N ha–1 and A. afraspera even accumulated 196 kg N ha–1 in the shoots. In all treatments, green manure increased grain yield significantly (P=0.05) over the untreated control, by 1.3–1.7 Mg ha–1. The yields were comparable to those obtained with 60 kg N ha–1 of urea fertilizer. S. rostrata caused the highest grain yield, of 6.5 Mg ha–1 on the Maahas clay soil of IRRI. The apparent release of exchangeable NH 4 + -N in the soils after green manuring and the rice grain yield response showed that both green manure species may provide sufficient available N throughout the development of IR 64 in the wet season. In the rainfed marginal soil site, green manure with S. rostrata produced even higher rice grain yields than urea. Green manure therefore seems particularly attractive for poor farmers on marginally productive soils, at least as a temporary strategy to improve yield and yield sustainability.  相似文献   

4.
有机物料与化肥配施提高黄泥田水稻产量和土壤肥力   总被引：14，自引：1，他引：13  
农业有机物料具有资源化再利用的特点,与化肥配施既可以保证作物产量,也可以提升地力。为了建立最适宜的南方低产黄泥田培肥模式,该文在浙江金衢盆地开展3年田间试验研究化肥与不同有机物料(菇渣、紫云英、牛粪和秸秆)配施对水稻产量和土壤肥力的影响。结果表明:1)有机物料与化肥配施可以显著提高水稻产量,化肥+菇渣、化肥+紫云英、化肥+牛粪和化肥+秸秆处理下,水稻三年的平均产量分别比单施化肥提高了9.7%、9.5%、12.3%和9.5%;2)有机物料与化肥配合施用,土壤有机质、土壤养分(全氮、有效磷、速效钾和CEC)及土壤容重较单施化肥处理有一定程度的改善,其中,化肥+牛粪效果最明显,有机质质量分数提高了12.5%,土壤有效磷质量分数提高了37.7%,CEC提高了16.1%;3)与单施化肥相比,化肥+菇渣、化肥+牛粪处理下5 mm机械稳定性大团聚体分别提高了10.4%和6.7%,各配施处理均显著降低了团聚体破坏率。总得来讲,连续三年有机物料与化肥配施较单施化肥处理提高了水稻产量、改善了土壤肥力状况、增加了土壤团聚体稳定性,其中又以牛粪与化肥配合施用效果最佳。  相似文献   

5.
长期施用不同有机肥对甘薯产量和土壤生物性状的影响   总被引：3，自引：1，他引：2  
以花生—甘薯轮作的长期定位试验为研究对象,研究不同(类)有机肥对甘薯产量、土壤微生物丰度和酶活性的影响,为选取合适的有机肥在提高作物产量和改善土壤生物性状方面提供依据。共选取5个施肥处理:(1)CK,空白对照;(2)NPK,单施化肥;(3)NPK+SR,化肥+稻草;(4)NPK+M,化肥+商品有机肥;(5)NPK+P,化肥+猪粪。结果表明:与CK相比,NPK、NPK+SR、NPK+M和NPK+P处理均显著增加鲜薯产量和地上部生物量(P<0.05),其中NPK+P处理效果最好。与CK比较,NPK处理显著降低土壤细菌、真菌、固氮菌和活化有机磷微生物的丰度(P<0.05),而NPK+SR、NPK+M和NPK+P处理在不同程度上缓解了NPK处理对土壤微生物丰度的抑制作用。土壤酶的加权平均值(GMea)在一定程度上可用来评价土壤酶的总体活性。与CK相比,NPK、NPK+SR和NPK+M处理的土壤酶活性显著降低(P<0.05),而NPK+P处理的土壤酶活性有所提高;对于土壤单一酶活性,NPK+P处理与CK比较显著降低土壤脲酶活性(P<0.05),但显著提高酸性磷酸酶、碱性磷酸酶和过氧化氢酶活性。此外,主成分和相关性分析表明,土壤养分和土壤有机碳与鲜薯产量和地上部生物量显著正相关,土壤pH是驱动土壤微生物丰度和土壤酶活性变化的主要因素。因此,长期有机无机肥配施通过提高土壤养分、有机碳含量以及调节土壤pH变化在提高甘薯产量和改善土壤生物性状方面取得良好效果。总体来说,化肥配施猪粪在培肥地力和增产增收方面效果最佳。  相似文献   

6.
Imbalanced fertilizer use with intensive cropping has threatened the sustainability of agroecosystems, especially on acid soils. An understanding of the long-term effects of fertilizers and amendments on soil health is essential for sustaining high crop yields. The effects of application of fertilizers, and amendments for 46 years on soil properties and maize yield in an acid Alfisol were investigated in this study. Ten fertilizer treatments comprising different amounts of NPK fertilizers, farmyard manure (FYM) and lime, and one control, were replicated three times in a randomized block design. At 0–15 cm soil depth, bulk density was least (1.20 t/m3), porosity (49.8%) and water holding capacity (61.7%) were greatest in 100% NPK + FYM, corresponding to the largest organic carbon content (13.93 g/kg). Microbial biomass C and dehydrogenase activity in 100% NPK + FYM were 42% and 13.7% greater than 100% NPK, respectively. Available nutrients were significantly more with 100% NPK + FYM and 100% NPK + lime than control and other fertilizer treatments. At 15–30 cm depth, the effect of various treatments was comparable to the surface layer. Grain yield declined by 55% and 53% in 100% NPK(-S) and 100% NP, respectively, compared with 100% NPK, whereas 100% N as urea alone eventually led to crop failure. Soil porosity recorded the greatest positive correlation (r = .933**), whereas bulk density recorded a negative significant correlation (r = −.942**) with grain yield. The results suggest that integrated use of FYM/lime with chemical fertilizers is a sustainable practice in terms of crop yield and soil health, whereas continuous application of urea alone is detrimental to the soil health.  相似文献   

7.
Organics, biological, and inorganic fertilizers play a crucial role for improving crop yield and soil properties. Accordingly, we assessed their impact on yield, microbial activities, and transformations of carbon (C), nitrogen (N), phosphorus (P), and sulfur (S) in soils under a 12-year-old intensively cultivated rice (Oriza sativa L.), mustard (Brassica juncea L.), sesame (Sesamum indicum L.) system with sole inorganic (NPK); NPK + farmyard manure (NPKF); NPK + green manure (NPKG) (Sesbania sesban L.), and NPK + green manure + bio-fertilizer (NPKGB) (Azotobacter chroococcum+ pseudomonas putida) treatments in sub-tropical India. The system yield was much higher with NPKF (23%) and NPKGB (18%) than that with NPK. Organic supplementation had a favorable influence on soil microbial biomass C (Cmic), N (Nmic), and activities of extracellular enzymes. Results of principal component and multiple regression analyses showed significant influence of Cmic on system yield (R2 = 91, p = 0.001) and S availability (R2 = 62, p = 0.001). Similarly, mineralizable N and acid phosphatase could predict significantly soil available N (R2 = 85, p = 0.001) and P (R2 = 51; p = 0.001), respectively. Results thus indicated that integrated nutrient management (NPKF/G) improved system yield, nutrient accumulation, and microbial activities in soils.  相似文献   

8.
张奇春  王光火  方斌 《土壤学报》2005,42(1):116-121
在水稻长期定位肥料试验条件下研究了不同施肥处理对水稻养分吸收动态变化和土壤微生物生态特性的影响。该长期定位试验设有CK(不施肥对照)和PK、NK、NP、NPK五个肥料处理和常规稻、杂交稻品种对比处理。研究结果表明,水稻产量分别与水稻吸氮总量、吸磷总量和吸钾总量显著相关;在连续种植水稻条件下,水稻对所缺养分的吸收量呈逐年下降趋势,表明缺肥区土壤相应的有效养分库消耗很快。土壤微生物特性测定表明,不平衡施肥降低了土壤微生物量N,使微生物量C/N比增加。与缺肥区相比较,NPK配施处理促进了土壤微生物的功能多样性,同时增加了土壤微生物总量。可见,土壤中养分不足或供应不平衡,不仅影响水稻养分的吸收,而且对土壤微生物总量和群落多样性产生重要影响。  相似文献   

9.
Summary Two annual species of Sesbania, S. aculeata and Sesbania sp. PL Se-17, were field evaluated as green manure for wetland rice in an alkaline soil. The two species were raised as a catch crop during summer in a wheat-rice rotation, and added as 24.7 and 20.8 t ha–1 of green matter, 116 and 98 kg N ha–1, respectively, after 45 days of growth. For the optimum green manuring effect on rice grain yield and N uptake, S. aculeata required 5 days of decomposition (after turning in and before rice transplantation), whereas no decomposition period was necessary for Sesbania sp. PL Se-17. The effect on grain yield and N uptake of rice was equivalent to an application of 122 and 78 kg ha–1 of chemical N, for the two species, respectively. There was no residual effect of the green manuring on the soil N status after rice harvest.  相似文献   

10.
Summary We used 15N technology to investigate N2 fixation by Sesbania speciosa and Sesbania rostrata and its transfer to a lowland rice crop after incorporation of the Sesbania spp. into soil as green manure. During the first 50 days after establishment in November–December 1989, S. speciosa and S. rostrata produced 1126 and 923 kg dry matter ha-1 respectively. They gathered 31 and 23 kg N ha-1 respectively, of which 62%±5% and 55%±3% respectively, came from N2 fixation. Both these species produced a greater biomass during September–October 1989, with S. rostrata producing more than S. speciosa. These results reflected differential responses by the plants to different day lengths at different times of the year. Furthermore, the dry matter yield and %N of 15N-labelled S. speciosa were smaller than those of the unlabelled plants, possibly due to inhibition of N2 fixation in root nodules by the chemical N fertilizers added during labelling. These differences were not so pronounced in the stem-nodulated S. rostrata. The increased grain yield of rice fertilized with N in the form of chemical fertilizer or green manure was a result of an increased number of panicles per hill. The rice crop manured with S. speciosa produced a lower grain yield, with a lower grain weight than that manured with S. rostrata. This was due to a low uptake of soil N by rice manured with S. speciosa. Recovery of N from the green manure in rice straw with S. speciosa was significantly higher than from rice manured with S. rostrata, because of the higher applied N uptake by rice manured with the former.  相似文献   

11.
We have studied the influence of long-term fertilization on organic C, nutrients, microbial biomass of soil, and grain yield of rice (Oryza sativa L.) after 18 years of inorganic and organic fertilizer application to an infertile paddy field under subtropical conditions. After 18 years of fertilization, soil organic C and total N contents were 9.56~12.17 and 1.01~1.25 g kg−1, which were 190~269% and 135~191% higher than those of the initial soil, respectively. Organic manure application increased soil organic C, total N, available N, and available P contents by 19.2%, 14.4%, 13.2%, and 78.3% on average compared with organic manure-omitted treatments. Phosphorus fertilizer application increased soil available P content more significantly than organic manure application, and it was an average 385% higher than P-omitted treatments. Soil microbial biomass C, N, and rice yield were 48.9%, 33.2%, and 133% higher in organic manure application treatments and 36.8%, 38.8%, and 239% higher in P fertilizer application treatments than organic manure-omitted or P-omitted treatments, respectively. Incorporation of organic manure-enhanced and P fertilizer-enhanced rice yields by 382% compared with the unfertilized treatment and yield increment index was 123% compared with that observed during 1991–1994, implying that organic manure application combined with P fertilizer was needed to ensure high and sustainable productivity. Rice yield was significantly correlated with all soil chemical properties except available K content, and stepwise regression analysis showed that soil available P content was the limiting factor to rice yield.  相似文献   

12.
有机无机肥配施对潜育化水稻土的改良效应   总被引：1，自引：0，他引：1  
为探索潜育化水稻土改良培肥措施,采用田间试验研究了工程排水条件下有机无机肥配施对潜育化低产水稻土的改良效应。结果显示:有机无机肥配施增加了早、晚稻的有效分蘖数。在早稻齐穗期,与CK和NPK处理相比,有机无机肥配施的叶绿素(SPAD值)均显著增加。有机无机肥配施显著增加了晚稻的产量,与NPK处理相比,产量增加了10.0%~23.7%;其中早稻配施紫云英、晚稻配施猪粪处理产量最高。在工程排水基础上,配施有机肥处理在早、晚稻收获时耕层土壤还原物质总量分别比单施化肥处理减少了15.0%~25.3%和32.5%~37.5%。这表明,在工程排水条件下,配施一定的有机肥可以明显提高潜育化稻田水稻产量,降低表层土壤还原物质总量,对改良潜育化水稻土有明显作用。  相似文献   

13.
Sustainability index was calculated to assess soil quality under the influence of different fertilizer management practices. It is based on the area of the triangle in which nutrient index, microbial index and crop index of soil represented the three vertices of a triangle. Nutrient index reflected the nutrient status of soil and was calculated from the measurements of various soil chemical parameters. Microbial index was calculated by determining various soil microbial and biochemical activities and crop index by measuring of crop yield parameters. Eighteen soil indicators were determined to assess nutrient index, microbial index and crop index in order to compare the effect of different sources of nutrients such as green manure, farmyard manure and chemical fertilizer in a rice/corn–wheat rotation. The indices were applied to assess the sustainability of five field experiments with respect to the different fertilizer treatments. The long-term application of organic manures in rice/corn–wheat cropping system increased the index value because it increased the nutrient index, microbial index and crop index of soils. The use of only chemical fertilizers in the rice–wheat cropping system resulted in poor soil microbial index and crop index. In corn–wheat system, additional application of FYM at 10 t ha–1 before sowing corn made the system more sustainable than application of 100%NPK; the sustainability index values were 2.43 (the highest for this system) and 0.93, respectively.  相似文献   

14.
Changes in the soil microbial biomass following applications of farmyard manure and inorganic fertilizer, alone and in combination, were studied for two annual cycles in a rice-lentil crop sequence grown under rainfed tropical dryland conditions. During the two annual cycles the microbial biomass C range (g g-1) was 146–241 (x = 204), 191–301 (245), 244–382 (305), and 294–440 (365) in control, fertilizer, manure and manure+fertilizer plots, respectively. The corresponding ranges for microbial biomass N (g g-1) were 16.5–21.0 (19.5), 20.4–38.2 (26.0), 23.0–34.6 (27.0) and 26.2–42.4 (33.3), and for microbial biomass P (g g-1) 4.4–8.2 (7.0) 6.0–11.2 (9.6), 11.2–22.0 (17.0), and 10.0–25.4 (18.3). The maximum increase in the microbial biomass, due to these inputs was observed under the manure+fertilizer treatment followed, in decreasing order, by manure alone and fertilizer alone. Within individual crop periods the levels of microbial biomass decreased sharply from the seedling to the flowering stage and then increased slightly with crop maturity. The maximum levels of microbial biomass C and P were observed during the summer fallow. The maximum accumulation of microbial biomass N occurred in the early rainy season, immediately after the soil amendments. Microbial biomass C, N, and P were positively related to each other throughout the annual cycle.  相似文献   

15.
长期施肥红壤稻田有机碳演变规律及影响因素   总被引：9，自引：0，他引：9  
利用1981年起设置的水稻土长期施肥定位试验,分析了CK(不施肥)、N(单施氮肥)、NPK(氮磷钾配施)、NPK2(2倍氮磷钾配施)和NPKM(有机无机肥配施)等施肥措施下土壤有机碳的演变规律及其与作物产量和土壤养分(全氮、碱解氮、全磷、速效磷、全钾和速效钾)的相关性.结果表明:试验30年后,各个处理的土壤有机碳含量均有上升,其中CK、N、NPK、NPK2和NPKM的土壤有机碳在试验30年分别比试验前增加18.95％、17.72％、23.36％、16.92％和32.68％.与CK处理相比,NPK、NPK2和NPKM处理的土壤有机碳平均提高了4.09％、4.03％和25.68％.土壤有机碳含量与水稻产量呈显著相关(P＜0.001),相关系数r为0.410,这说明土壤有机碳含量的增加可以促进水稻增产.土壤有机碳与土壤养分中的碱解氮、速效磷和全磷含量均表现出极显著相关(P＜0.001),相关系数r分别为0.452、0.559和0.487,但是与钾含量相关不显著.这表明:有机无机肥配施可以持续快速提高红壤性水稻土的有机碳含量,同时在有机无机肥配施过程中应适当增施钾肥,从而促进土壤肥力平衡和维持作物高产稳产,实现农业可持续性.  相似文献   

16.
  【目的】  依托位于江西红壤研究所的有机肥长期定位试验，探究长期施用紫云英、猪粪和秸秆还田对土壤微生物量、酶活性和产量的影响，阐明土壤微生物学特性对土壤肥力的生物指示功能，揭示影响作物产量和微生物学特性的关键环境因子。  【方法】  长期定位试验始于1981年，选取的6个处理分别为:CK (不施肥)、NPK (单施化肥)、M1 (早稻施绿肥)、M2 (早稻加倍施绿肥)、M3 (早稻施绿肥+晚稻施猪粪) 和M4 (早稻施绿肥+晚稻秸秆还田)，此外，有机处理 (M1、M2、M3和M4) 在施用有机物料的基础上，每季还补充一定量化肥（N 69 kg/hm2、P2O5 30 kg/hm2、K2O 67.5 kg/hm2）。于每季收获后测定水稻产量。2018 年早稻收获后，采集耕层 (0—20 cm)土壤，测定土壤化学指标、微生物量碳氮、脲酶及其他参与土壤碳、氮、磷和硫循环的胞外酶活性。  【结果】  1) 2009—2018年间，长期施肥处理明显提高了水稻产量，其中M3处理的产量最高，其次为M2处理，二者均明显高于NPK处理；2) 土壤微生物量及酶活性均以有机处理 (M1、M2、M3和M4) 较高，其中M3处理土壤微生物量碳含量及各类土壤酶活性最高，M2处理土壤微生物量氮含量最高。有机处理较CK和NPK处理提高了土壤微生物熵。此外，微生物量碳氮和土壤酶活性与有机碳、全氮间存在显著或极显著相关关系；3) 有机碳与土壤微生物量 (0.895)、碳循环相关酶活性 (0.903)、氮循环相关酶活性 (0.854) 及水稻产量 (0.827) 呈显著正影响 (P < 0.05)；土壤pH与土壤碳循环相关酶活性 (0.378) 和氮循环相关酶活性 (0.365) 呈显著正影响 (P < 0.05)，对水稻产量 (0.211) 也表现为正影响，但不显著 (P > 0.05)。相较于pH，土壤有机碳含量在提高水稻产量、改善土壤微生物学特性上发挥了更为重要的作用。  【结论】  土壤微生物量碳氮和参与土壤碳、氮、磷和硫循环的胞外酶活性均可作为土壤微生物学指标表征土壤肥力的变化。土壤有机碳含量是提高作物产量、调控土壤微生物量和酶活性的关键因子。在供试条件下，长期实行早稻施绿肥+晚稻施猪粪的有机培肥，是提高土壤微生物量及酶活性并提高水稻产量的最佳选择。  相似文献   

17.
Long‐term applications of inorganic fertilizers and farmyard manure influence organic matter as well as other soil‐quality parameters, but the magnitude of change depends on soil‐climatic conditions. Effects of 22 annual applications (1982–2003) of N, P, and K inorganic fertilizers and farmyard manure (M) on total organic carbon (TOC) and nitrogen (TON), light‐fraction organic C (LFOC) and N (LFON), microbial‐biomass C (MB‐C) and N (MB‐N), total and extractable P, total and exchangeable K, and pH in 0–20 cm soil, nitrate‐N (NO ‐N) in 0–210 cm soil, and N, P, and K balance sheets were determined using a field experiment established in 1982 on a calcareous desert soil (Orthic Anthrosol) at Zhangye, Gansu, China. A rotation of irrigated wheat (Triticum aestivum L.)‐wheat‐corn (Zea mays L.) was used to compare the control, N, NP, NPK, M, MN, MNP, and MNPK treatments. Annual additions of inorganic fertilizers for 22 y increased mass of LFON, MB‐N, total P, extractable P, and exchangeable K in topsoil. This effect was generally enhanced with manure application. Application of manure also increased mass of TOC and MB‐C in soil, and tended to increase LFOC, TON, and MB‐N. There was no noticeable effect of fertilizer and manure application on soil pH. There was a close relationship between some soil‐quality parameters and the amount of C or N in straw that was returned to the soil. The N fertilizer alone resulted in accumulation of large amounts of NO ‐N at the 0–210 cm soil depth, accounting for 6% of the total applied N, but had the lowest recovery of applied N in the crop (34%). Manure alone resulted in higher NO ‐N in the soil profile compared with the control, and the MN treatment had the highest amount of NO ‐N in the soil profile. Application of N in combination with P and/or K fertilizers in both manured and unmanured treatments usually reduced NO ‐N accumulation in the soil profile compared with N alone and increased the N recovery in the crop as much as 66%. The N that was unaccounted for, as a percentage of applied N, was highest in the N‐alone treatment (60%) and lowest in the NPK treatment (30%). In the manure + chemical fertilizer treatments, the unaccounted N ranged from 35% to 43%. Long‐term P fertilization resulted in accumulation of extractable P in the surface soil. Compared to the control, the amount of P in soil‐plant system was surplus in plots that received P as fertilizer and/or manure, and the unaccounted P as percentage of applied P ranged from 64% to 80%. In the no‐manure plots, the unaccounted P decreased from 72% in NP to 64% in NPK treatment from increased P uptake due to balanced fertilization. Compared to the control, the amount of K in soil‐plant system was deficit in NPK treatment, i.e., the recovery of K in soil + plant was more than the amount of applied K. In manure treatments, the recovery of applied K in crop increased from 26% in M to 61% in MNPK treatment, but the unaccounted K decreased from 72% in M to 37% in MNPK treatment. The findings indicated that integrated application of N, P, and K fertilizers and manure is an important strategy to maintain or increase soil organic C and N, improve soil fertility, maintain nutrients balance, and minimize damage to the environment, while also improving crop yield.  相似文献   

18.
Widespread yield stagnation and productivity declines in the rice–rice cropping system have been reported and many of the associated issues are related to soil quality. A long‐term experimental study was initiated in 1969 to assess the impact of continuous cultivation of rice as a single crop grown in wet as well as dry seasons using varying levels of chemical fertilizer and manure applications on soil quality indicators (physical, chemical and biological), a sustainable yield index (SYI) and a soil quality index (SQI). The treatments comprised chemical fertilizers and farmyard manure (FYM) either alone or in combination viz. control, N, NP, NK, NPK, FYM, N+FYM, NP+FYM, NK+FYM and NPK+FYM, laid out in a randomized complete block design with three replications. Soil samples were collected after the wet season rice harvest in 2010 and were analysed for physical, chemical and biological indicators of soil quality. A SYI based on long‐term yield data and SQI using principal component analysis (PCA) and nonlinear scoring functions were calculated. Application of NPK fertilizers in combination with FYM significantly increased the average grain yield of rice in both wet and dry seasons and enhanced the sustainability of the system compared to the control and plots in receipt of fertilizers. The SYI for the control was higher in the wet season than in the dry one, whereas the reverse was true for NPK+FYM treatment. The value of the dimensionless SQI varied from 1.46 in the control plot to 3.78 in the NPK+FYM one. A greater SYI and SQI in the NPK+FYM treatment demonstrated the importance of using a chemical fertilizer in combination with FYM. For the six soil quality indicators selected as a minimum data set (MDS), the contribution of DTPA‐Zn, available‐N and soil organic carbon to the SQI was substantial ranging from 59.4 to 85.7 per cent in NPK+FYM and control plots, respectively. Thus, these soil parameters could be used to monitor soil quality in a subhumid tropical rice–rice system.  相似文献   

19.
Summary A field trial was set up to examine the effect of green manuring, blue-green algae, and neem-cake-coated urea on a rice crop. Summer green manuring using Sesbania aculeata increased the crop yield. Inoculation of blue-green algae increased the rice grain yield when 60 kg N ha-1 was applied as prilled urea, but the increase in grain yield was greater when 60 kg N ha-1 was applied as neem-cake-coated urea. The results of the present study show that applications of green manure, neem-cake-coated urea, and blue-green algae are complementary and that the three treatments can be used together in the rice ecosystem. The green manure and the fertilizer treatments had no effect on the algal flora of the soil.  相似文献   

20.
皖南双季稻区长期施肥效应研究   总被引：7，自引：0，他引：7  
在安徽休屯盆地进行的10年肥料定位试验结果表明,土壤对水稻产量的贡献率明显大于肥料,施肥的增产幅度随施肥年限有逐年降低趋势。氮磷钾肥增产效应依次为K＞N＞P。长期施用有机肥可保持水稻稳定增产,但在等养分条件下,紫云英与氮磷钾化肥配施（MNP）,早稻平均产量明显低于等养分的化服单施（NPK）,说明有机肥应提早施人,并增加氮肥作基肥的比例,以满足水稻幼苗对养分的需求。施用化肥或有机肥除有效钾外,土壤养分均有增加。因此从增产增收和养分平衡的意义上讲,必须重视稻田施用钾肥,适当控制磷肥用量。  相似文献   

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