Influence of Soil and Fertilizer Nutrients on Sustainability of Rainfed Finger Millet Yield and Soil Fertility in Semi-arid Alfisols

Productivity of rainfed finger millet in semiarid tropical Alfisols is predominantly constrained by erratic rainfall, limited soil moisture, low soil fertility, and less fertilizer use by the poor farmers. In order to identify the efficient nutrient use treatment for ensuring higher yield, higher sustainability, and improved soil fertility, long term field experiments were conducted during 1984 to 2008 in a permanent site under rainfed semi-arid tropical Alfisol at Bangalore in Southern India. The experiment had two blocks—Farm Yard Manure (FYM) and Maize Residue (MR) with 5 fertilizer treatments, namely: control, FYM at 10 t ha^?1, FYM at 10 t ha^?1 + 50% NPK [nitrogen (N), phosphorus (P), potassium (K)], FYM at 10 t ha^?1 + 100% NPK (50 kg N + 50 kg P + 25 kg K ha^?1) and 100% NPK in FYM block; and control, MR at 5 t ha^?1, MR at 5 t ha^?1 + 50% NPK, MR at 5 t ha^?1 + 100% NPK and 100% NPK in MR block. The treatments differed significantly from each other at p < 0.01 level of probability in influencing finger millet grain yield, soil N, P, and K in different years. Application of FYM at 10 t ha^?1 + 100% NPK gave a significantly higher yield ranging from 1821 to 4552 kg ha^?1 with a mean of 3167 kg ha^?1 and variation of 22.7%, while application of maize residue at 5 t ha^?1 + 100% NPK gave a yield of 593 to 4591 kg ha^?1 with a mean of 2518 kg ha^?1 and variation of 39.3% over years. In FYM block, FYM at 10 t ha^?1 + 100% NPK gave a significantly higher organic carbon (0.45%), available N (204 kg ha^?1), available P (68.6 kg ha^?1), and available K (107 kg ha^?1) over years. In maize residue block, application of MR at 5 t ha^?1 + 100% NPK gave a significantly higher organic carbon (0.39%), available soil N (190 kg ha^?1), available soil P (47.5 kg ha^?1), and available soil K (86 kg ha^?1). The regression model (1) of yield as a function of seasonal rainfall, organic carbon, and soil P and K nutrients gave a predictability in the range of 0.19 under FYM at 10 t ha^?1 to 0.51 under 100% NPK in FYM block compared to 0.30 under 100% NPK to 0.67 under MR at 5 t ha^?1 application in MR block. The regression model (2) of yield as a function of seasonal rainfall, soil N, P, and K nutrients gave a predictability in the range of 0.11 under FYM at 10 t ha^?1 to 0.52 under 100% NPK in FYM block compared to 0.18 under MR at 5 t ha^?1 + 50% NPK to 0.60 under MR at 5 t ha^?1 application in MR block. An assessment of yield sustainability under different crop seasonal rainfall situations indicated that FYM at 10 t ha^?1 + 100% NPK was efficient in FYM block with a maximum Sustainability Yield Index (SYI) of 41.4% in <500 mm, 64.7% in 500–750 mm, 60.2% in 750–1000 mm and 60.4% in 1000–1250 mm rainfall, while MR at 5 t ha^?1 + 100% NPK was efficient with SYI of 29.6% in <500 mm, 50.2% in 500–750 mm, 40.6% in 750–1000 mm, and 39.7% in 1000–1250 mm rainfall in semi-arid Alfisols. Thus, the results obtained from these long term studies incurring huge expenditure provide very good conjunctive nutrient use options with good conformity for different rainfall situations of rainfed semiarid tropical Alfisol soils for ensuring higher finger millet yield, maintaining higher SYI, and maintaining improved soil fertility.     

耕作与轮作方式对黑土有机碳和全氮储量的影响

土壤有机碳(SOC)及全氮(TN)对土壤肥力、作物产量、农业可持续发展以及全球碳、氮循环等都具有重要影响。为探索不同耕作和轮作方式对耕层黑土SOC和TN储量的影响,本文以吉林省德惠市进行了8 a的田间定位试验中层黑土为研究对象,对免耕、垄作和秋翻三种耕作方式及玉米-大豆轮作和玉米连作两种轮作方式下SOC和TN在各土层的含量变化进行了分析,并采用等质量土壤有机质储量计算方法,对比分析了不同处理对0～30 cm SOC和TN储量的影响。结果表明,与试验开始前相比,玉米-大豆轮作系统中,秋翻下SOC和TN储量均有所降低;免耕显著增加了0～5 cm SOC及TN含量,但SOC在亚表层亏损,导致其储量并未增加;而垄作处理下SOC及TN含量在0～5、5～10 cm的均显著增加,0～30 cm储量亦分别增加了4.9%和10.7%。玉米连作系统的两种耕作处理(免耕和秋翻)下SOC和TN储量均有所增加,且TN储量增幅均高于玉米-大豆轮作系统,其中免耕下TN储量增幅是玉米-大豆轮作的3.2倍。所有处理下C/N均呈降低趋势,其中垄作0～5 cm C/N由12.05降至11.04,降低幅度分别是免耕和秋翻的3.2和2.8倍。综上可知,对质地黏重排水不良的中层黑土,玉米-大豆轮作系统下免耕并不是促进SOC固定的有效形式,而垄作则促进了黑土SOC和TN的积累,这不仅有利于土壤肥力的改善,而且是使农田黑土由CO2"源"变为"汇"的有效形式之一。与玉米-大豆轮作相比,玉米连作下三种耕作方式都有利于SOC和TN积累。     

Green manure rotation and application increase rice yield and soil carbon in the Yangtze River valley of China

The addition of organic matter via green manure rotation with rice is considered a smart agricultural practice to maintain soil productivity and support environmental sustainability. However, few studies have quantitatively assessed the impact of green manure rotation and application on the interactions between agronomic management practice, soil fertility, and crop production. In this study, 800 pairs of data from 108 studies conducted in the agricultural region of the Yangtze River, China were...     

秸秆还田配施化肥对稻油轮作土壤有机碳组分及产量影响

【目的】水稻-油菜轮作是我国重要的农业种植模式。秸秆还田是目前我国秸秆利用最主要、最直接的途径。因此,研究水稻-油菜轮作系统下,秸秆还田配施化肥对水稻和油菜产量、土壤有机质组分及其养分含量的影响,有助于提高水稻和油菜产量,培肥土壤,推进秸秆还田技术的应用。 【方法】通过水稻和油菜7年13季作物的田间定位小区试验,设置了不施氮肥不还田处理（CK）、农民习惯处理（FPP）和3个秸秆还田配施化肥处理（SF1、SF2、SF3:每年水稻秸秆以3000 kg/hm2的量还田,配施不同量氮、磷、钾肥）,分析了各处理土壤有机碳及其组分、土壤养分含量、作物产量和经济效益。 【结果】与不施氮肥处理比较,秸秆还田配合氮、磷、钾平衡施肥能显著提高土壤总有机碳及其各组分、土壤养分含量、作物产量和经济效益。与农民习惯处理相比,秸秆还田配施化肥处理土壤总有机碳、胡敏酸和胡敏素分别显著增加了5.62%~12.08%、9.05%~22.57%和7.93%~10.23%,而水溶性有机碳和富里酸含量差异则不明显;土壤全氮、有效磷和速效钾含量分别显著提高了6.74%~14.04%、134.67%~249.46%和40.18%~70.54%;水稻、油菜和周年平均产量分别增加了8.55%~19.34%、19.06%~27.27%和10.34%~24.08%;净利润提高了1651~4905 yuan/hm2,但总投入增加了1427~2882 yuan/hm2。秸秆还田配施化肥处理中,以氮、磷、钾肥用量与运筹次数最多的SF3处理土壤各项指标、作物产量和经济效益最高,与之相比,SF2处理在水稻和油菜两季共减少肥料用量255 kg/hm2,而作物周年产量减少不明显。土壤有机碳组分、土壤养分含量及作物产量之间有较好的相关性,而逐步回归分析表明,土壤总氮、胡敏酸、水溶性有机碳含量是水稻和油菜产量主要决定因素。 【结论】秸秆还田配施化肥可以提高土壤有机碳、胡敏酸、胡敏素含量及土壤养分含量,培肥土壤并提高其稳定性,促进作物增产。虽然秸秆还田配施化肥增加了人工和肥料投入,但适宜的化肥用量配合秸秆还田提高了水稻油菜轮作体系的经济效益。     

缓释氮肥运筹对稻麦轮作周年作物产量和氮肥利用率的影响

【目的】稻麦轮作是我国一种重要的农业种植模式。缓/控释肥作为高效兼环境友好的肥料类型,在多种作物单季种植上具有增产和提高肥效的作用,但是缓释肥在周年轮作体系中的肥效研究鲜有报道。因此研究稻麦轮作体系中的肥料施用模式,有助于提高稻麦产量,降低化肥用量,提高化肥利用率。【方法】本文通过稻麦轮作两周年四季作物的田间小区试验,以不施氮和习惯施氮为对照,研究了4种不同缓释肥减氮处理[进口树脂包膜尿素减氮24.3%、 国产硫包衣尿素减氮24.3%、 国产尿素加NAM(长效氮肥添加剂)减氮24.3%和国产尿素加NAM减氮10.8%]对水稻和小麦产量、 氮肥利用率、 第二周年稻麦收获后土壤养分含量和两周年土壤氮养分表观平衡的影响。【结果】与不施氮对照相比,所有施氮处理均提高了两周年稻麦4季作物产量,习惯施氮增产幅度最高,小麦的氮肥增产效果总体高于水稻,第二周年高于第一周年; 与当地习惯施氮量相比,所有的缓释氮肥减氮24.3%或10.8%处理均无显著降低两季小麦产量,进口树脂包膜尿素减氮24.3%处理和国产尿素加NAM减氮10.8%处理也无显著降低两季水稻产量,但是国产尿素加NAM减氮24.3%处理显著降低了第二季水稻产量,国产硫包衣尿素减氮24.3%显著降低了两季水稻产量; 与当地习惯施氮量相比,4个缓释氮肥减氮处理均提高了第一和第二周年氮肥利用率,显著降低了两周年稻田土壤养分氮盈余量,其中国产尿素加NAM减氮24.3%处理氮肥利用率较高,同时土壤氮盈余量较少,说明缓释氮肥减量在提高肥料利用率和降低氮的环境效应上具有一致的优势; 不同缓释氮肥对土壤养分含量的影响无明显规律性。【结论】在目前稻麦轮作体系中,缓释氮肥减施对小麦产量具有较好的稳定效果,但是个别缓释氮肥减施对水稻有减产风险,有必要依据稻田土壤氮素转化特点,研制水稻专用缓释氮肥,适当降低水稻季缓释氮肥的施用量。     

土壤地力和长期施肥对潮土区小麦和玉米产量演变趋势的影响

为潮土区合理施肥管理提供依据,对32个长期定位点、24年（1987～2010）不施肥和化肥配施秸秆（农民常规施肥）处理的小麦和玉米产量及其与土壤地力和施肥量间的关系进行了分析。结果表明:潮土区土壤地力对小麦和玉米产量的平均贡献率分别为51.4%和54.0%,变异系数分别为39.0%和41.2%。不施肥处理小麦和玉米产量每年分别下降4.1 kg/hm2和96.6 kg/hm2;常规施肥处理的小麦和玉米每年分别增产61.5 kg/hm2和26.8 kg/hm2。施化肥量与作物增产量（常规施肥产量－不施肥产量）呈显著正相关。通过通径分析进一步证明,施氮量对小麦产量具有显著直接作用。同时,磷肥对提高小麦和玉米的产量具有重要作用。总之,在农民习惯耕作施肥管理水平下,潮土区不施肥处理的产量下降缓慢（含品种对产量的贡献）,常规施肥区产量表现出缓慢增加的趋势。     

Critical carbon inputs to maintain soil organic carbon stocks under long‐term finger‐millet (Eleusine coracana [L.] Gaertn.) cropping on Alfisols in semiarid tropical India

Enrichment of soil organic carbon (SOC) stocks through sequestration of atmospheric CO₂ in agricultural soils is important because of its impacts on adaptation to and mitigation of climate change while also improving crop productivity and sustainability. In a long‐term fertility experiment carried out over 27 y under semiarid climatic condition, we evaluated the impact of crop‐residue C inputs through rainfed fingermillet (Eleusine coracana [L.] Gaertn.) cropping, fertilization, and manuring on crop yield sustainability and SOC sequestration in a Alfisol soil profile up to a depth of 1 m and also derived the critical value of C inputs for maintenance of SOC. Five treatments, viz., control, farmyard manure (FYM) 10 Mg ha^–1, recommended dose of NPK (50 : 50 : 25 kg N, P₂O₅, K₂O ha^–1), FYM 10 Mg ha^–1 + 50% recommended dose of NPK, and FYM 10 Mg ha^–1 + 100% recommended dose of NPK imposed in a randomized block design replicated four times. Application of FYM alone or together with mineral fertilizer resulted in a higher C input and consequently built up a higher C stock. After 27 y, higher profile SOC stock (85.7 Mg ha^–1), C build up (35.0%), and C sequestration (15.4 Mg C ha^–1) was observed with the application of 10 Mg FYM ha^–1 along with recommended dose of mineral fertilizer and these were positively correlated with cumulative C input and well reflected in sustainable yield index (SYI). For sustenance of SOC level (zero change due to cropping) a minimum quantity of 1.13 Mg C is required to be added per hectare per annum as inputs. While the control lost C, the application of mineral fertilizer served to maintain the priori C stock. Thus, the application of FYM increased the C stock, an effect which was even enhanced by additional amendment of mineral fertilizer. We conclude that organic amendments contribute to C sequestration counteracting climate change and at the same time improve soil fertility in the semiarid regions of India resulting in higher and more stable yields.     

有机-无机肥长期配施对潮土土壤肥力和作物产量的影响

以24年(19812～004年)的肥料长期定位试验为基础,分析探讨了有机-无机肥长期配施对潮土土壤肥力和作物产量的影响。研究结果表明,除增施秸秆外,增施化肥也能提高土壤有机质的含量,但同时增施化肥和秸秆更有利于土壤有机质的积累。在提高有机质复合量方面,施用化肥的效果好于施用秸秆,而有机-无机肥结合效果较单一施用秸秆或化肥都要高;随秸秆或化肥施用量的增加有机质的复合度逐渐降低,但有机-无机肥结合施用可以提高有机质的复合度。有机-无机结合有利于改善土壤的物理性状,降低了土壤容重,提高了土壤田间持水量和饱和含水量,增加了土壤总孔隙度和毛管孔隙。单施秸秆肥和单施化肥均有显著的增产效应,而化肥的增产幅度远远大于秸秆肥,有机-无机结合的增产幅度在同等施肥量下较单独施用秸秆或化肥的产量都要高。结果表明,有机-无机结合较单一施用秸秆肥或化肥能更有效地提高潮土的土壤肥力,提高作物产量。     

Modeling of Soil-Plant-Fertilizer Relationships for Optimizing Fertilizer Doses for Different Levels of Finger Millet Yield under Semi-Arid Alfisols

Experiments were conducted to test the superiority of treatment combinations of nitrogen (N; 0, 50, 100, 150, 200 kg ha^?1), phosphorus (0, 30, 60, 90 kg ha^?1) and potassium (0, 30, 60 kg ha^?1) for finger millet during 2005–2007. Application of 200-90-60 kg ha^?1 gave maximum yield of 1666, 1426 and 1640 kg ha^?1 in 3 years, respectively. The yield regression model through soil and fertilizer nutrients gave predictability of 0.98, 0.97 and 0.98, with sustainability yield index (SYI) of 50.4, 49.4 and 52.5 in 2005, 2006 and 2007, respectively. Optimum nitrogen, phosphorus and potassium (NPK) doses for attaining yields of 800 and 1200 kg ha^?1 were derived at soil nitrogen, phosphorus and potassium of 75–400, 10–70 and 150–750 kg ha^?1. Fertilizer nitrogen, phosphorus and potassium ranged from 30–128, 3–19, 13–25 kg ha^?1 and 105–203, 4–32, 27–39 kg ha^?1 for attaining 800 and 1200 kg ha^?1 yield, respectively. The doses could be adopted for attaining sustainable yields under semiarid Alfisols.     

Impact of precursor crop and nitrogen fertilizer on the productivity of finger millet based cropping system and soil fertility in Lake Tana basin of Ethiopia

Abstract

Traditional short-term diversification of annual crops for the purpose of improving soil fertility and food security is a common practice in Ethiopia. However, the best cropping systems have not been selected yet though field research. Experiments were conducted for two years with an objective of establishing sustained finger millet based short term cropping sequence in two major finger millet producing areas of Ethiopia. The experiments were laid out in a split-plot arrangement with six precursor crops (haricot bean, maize, sweet lupine, niger seed, wheat, and teff) as a main plot factor, where determined residues were retained in the main plot after harvesting and two nitrogen fertilizer levels (30 and 60?kg ha^?1) applied for finger millet as sub-plots with three replications. Soil analysis result examined immediately after finger millet harvest showed a significant effect of precursor crops and nitrogen fertilizer rates on soil properties. Planting finger millet following lupine increased the soil organic carbon, total nitrogen and cation exchange capacity by 17.37%, 65.50%, 26.15%, respectively, over planting finger millet following teff. Use of different amount of nitrogen fertilizer likely contributed to observed differences in residual soil nutrients. Accordingly, finger millet following lupine with the addition of 60?kg ha^?1 nitrogen fertilizer gave significantly higher finger millet grain yield (3.24 tone ha^?1) and relative production (22.37%) and economic (40.7%) efficiency. This system with their high sustainability and multiple benefits can be readily accepted by the farming community.     

Effect of biochar amendment on soil physical,chemical and biological properties and groundnut yield in rainfed Alfisol of semi-arid tropics

The aim of this study was to evaluate the effect of biochar and organic soil amendments on soil physicochemical and microbial load, carbon sequestration potential, nutrient uptake and yield of groundnut in acidic red soil under rainfed condition. Biochar was prepared from red gram, cotton, maize stalk and mesquite wood using pilot scale slow pyrolysis biochar unit. The above sources of biochar at the rate of 2.5 and 5 t ha^?1 and enriched farmyard manure 0.75 t ha^?1, composted coir pith 10 t ha^?1 and arbuscular mycorrhizae 100 kg ha^?1 were applied as basal with required nitrogen, phosphorous and potassium fertilizer. Biochar amendment at the rate of 5 t ha^?1 reduced the bulk density from 1.41 to 1.36 g cm^?3 and increased the soil moisture 2.5%. With respect to soil chemical changes, it raised soil pH from 5.7 to 6.3; increased the cation exchange capacity 1.4 cmol⁺ kg^?1 and enhanced the carbon buildup 4.4 t ha^?1. The significant differences in bacteria, fungi and actinomycetes population were observed between biochar and control. The nitrogen, phosphorous and potassium were better utilized under biochar and composted coir pith, which was 21, 5 and 20 kg ha^?1 higher than control. The experimental results suggested that application of biochar to acidic red soil favoured good soil physical, chemical and biological environment, and these positive changes influenced growth and yield attributes and enhanced pod yield 29% over control.     

Organic residues and their impact on soil health,crop production and sustainable agriculture: A review including bibliographic analysis

Despite their potential as a sustainable source of soil nutrients and organic matter, waste organic residues are often discarded rather than utilized in agriculture. This review examines the current state-of-the-art in the application of organic residues in agricultural production systems by analysing trends and results in published research conducted on their use for soil health and crop production purposes. For this, a bibliographic analysis was conducted on 81 papers collected from the Web of Science database. Our research shows a growing trend in the field, particularly in recent years, with articles from India, China and the United States at the forefront. The most commonly evaluated organic residues were compost, animal manure, crop residues, municipal solid waste and biochar. Soil pH, bulk density and especially organic matter/total organic carbon (TOC) were the chemical, physical and biological attributes most frequently evaluated, respectively. This review indicates that the application of organic residues improves soil health, positively affecting crop productivity in crops such as maize, wheat and rice. However, further research is needed to address the potential risk of soil contamination from potentially toxic metals (PTMs) associated with organic residues, as well as to identify best practices to guarantee food safety and environmental preservation.     

稻田绿肥轮作提高土壤养分增加有机碳库

综合评价中国南方不同稻田绿肥轮作模式,筛选与优化绿色高效的稻田多熟种植系统,有利于南方双季稻区农业可持续发展。通过田间试验,研究不同绿肥轮作模式(A冬闲-稻-稻→冬闲-稻-稻(对照)、B紫云英-稻-稻→油菜/花生-稻、C油菜/花生-稻→马铃薯/玉米+大豆-稻、D马铃薯/玉米+大豆-稻→蔬菜/花生+玉米-稻、E蔬菜/花生+玉米-稻→紫云英-稻-稻)对土壤养分中pH值、有机质、全氮、碱解氮、有效磷和速效钾及总有机碳库、活性有机碳、碳库管理指数的影响。结果表明:绿肥轮作各处理的土壤有机质、碱解氮和速效钾均显著高于对照处理(P0.05),增加幅度分别为8.73%~15.59%、11.79%~19.64%和5.80%~37.19%。绿肥轮作处理B、C的总有机碳质量分数与对照相比有显著(P0.05)增加,分别增加了15.59%、11.19%。与对照相比,绿肥轮作B、C、D、E均可以显著(P0.05)提升土壤活性有机碳质量分数,提高幅度分别为29.03%、19.96%、16.67%和21.75%。与冬闲对照处理相比,绿肥轮作系统中处理B的土壤碳库指数显著(P0.05)增加了15.70%。相比冬闲对照处理,绿肥轮作处理B、C、D、E的土壤碳库管理指数分别显著(P0.05)增加了32.07、21.32、17.91和23.74,其中紫云英-稻-稻→油菜/花生-稻种植模式达到最大。土壤有机质与全氮、有效磷、总有机碳、活性有机碳、碳库管理指数存在极显著(P0.01)的相关性,土壤全氮、碱解氮、有效磷均与碳库管理指数存在显著的相关性(P0.05)。此外,总有机碳与活性有机碳和碳库管理指数存在极显著的相关性(P0.01)。可见在当地土壤肥力条件下,绿肥轮作尤其是紫云英-稻-稻-油菜/花生-稻能提高土壤有机碳质量分数和土壤碳库管理指数,有利于改善土壤质量,提高土壤肥力,为建立农田可持续的土壤管理和土地利用提供科学依据和参考价值。     

A 60-years old field experiment demonstrates the benefit of leys in the crop rotation

In the 1950s, a long-term experiment was initiated at three locations in Northern Sweden. The treatments included four cropping systems, which differed in the number of years with leys or annual crops in the crop rotation. To create awareness of the experiment as a research resource for further scientific studies, we summarise the history (experimental design, materials and methods, main measurements) and scientific findings of the experiment, as well as reflect on its usefulness and opportunities for further studies. So far, scientific focus has been on the effects of cropping systems on soil characteristics. The main findings indicate that soil porosity and hydraulic conductivity were greater in cropping systems with a large proportion of ley, soil bulk density showed the opposite trend. In terms of chemical properties, cropping systems incorporating more ley also have greater soil organic carbon content than annual crops systems, and both soil carbon and N storage decrease over time in cropping systems with only annual crops. The effects of cropping system on crop yields and quality are areas for further investigation.     

Long‐term effects of organic manure and manufactured fertilizer additions on soil quality and sustainable productivity of finger millet under a finger millet–groundnut cropping system in southern India

In a 20‐yr‐old long‐term experiment, the impact of continuous application of organic manures and inorganic fertilizers on soil quality and the sustainability of finger millet production was conducted on two cropping systems: finger millet and finger millet–groundnut on an Alfisol of semi‐arid southern India. The study was conducted from 1992 to 2011 at the All India Coordinated Research Project for Dryland Agriculture, UAS, Bangalore, using a randomized block design. The treatments comprised of T₁: control [no fertilizer and no farmyard manure (FYM) applied], T₂: FYM 10 t/ha, T₃: FYM 10 t/ha + 50% of recommended NPK (50:50:25 kg/ha), T₄: FYM 10 t/ha + 100% of recommended NPK and T₅: 100% recommended NPK. Comparison of long‐term yield data between treatments was used to calculate a ‘sustainability yield index’ (SYI), which was greatest for T₄ (FYM 10 t/ha + 100% of recommended NPK), in both rotational (0.68) and monocropping (0.63) situations. Soil quality indices were determined using principal component analysis linear scoring functions. The key indicators which contributed to the soil quality index (SQI) under rotation were organic C; potentially available N; extractable P, K and S; exchangeable Ca and Mg; dehydrogenase activity and microbial biomass C and N. The largest SQI (7.29) was observed in T₄ (FYM 10 t/ha + 100% NPK), and the smallest (3.70) SQI was for the control. Application of 10 t/ha FYM together with NPK (50:50:25 kg/ha) sustained a mean yield of 3884 kg/ha.     

The effect of crop rotation and fertilization on dry matter yields and organic C content in soil in long-term field experiments in Prague

The dry matter yields of the main and second product in the years 2001–2010 and organic C content in 2007–2010 were used to evaluate the productivity of two rather different crop rotations, a 9-year crop rotation and an alternate growing of spring wheat and sugar beet in long-term field experiments in Prague. A comparative effect of farmyard manure and cattle slurry plus straw in combination with mineral fertilization was also evaluated. Crop rotation positively affected dry matter yields in the non-fertilized variants. The alternate growing of spring wheat and sugar beet was more dependent on external mineral nutrients input in order to reach yields comparable with crop rotation. There was no substantial difference in the effect of crop rotation on the organic C content in the topsoil. Mineral fertilizers significantly increased the organic C content in the topsoil compared with non-fertilized plots. The effect of mineral nitrogen fertilizers on simplified carbon balance was strongly positive, whereas its effect on nitrogen balance was slightly positive. There was no significant difference between the effects of farmyard manure and cattle slurry plus straw on the dry matter yields of crops.     

Soil organic carbon fractions and management index after 20 yr of manure and fertilizer application for greenhouse vegetables

Impacts of organic manure and inorganic fertilizer on total organic carbon (C_T), water‐soluble organic C (C_WS), microbial biomass C (C_MB), particulate organic C (C_P), labile organic C (C_L), C storage and sequestration, and C management index (CMI) in surface soil (0–20 cm) were investigated in a 20‐yr field experiment under a greenhouse vegetable system in northeast China. The treatments included unfertilized control (CK), N fertilizer (N), balanced NPK fertilizer (NPK), organic manure alone (M) and the NPK fertilizer combined with the manure (MNPK). Under the treatments of N and NPK, C_T content and C storage were not significantly changed over the experimental period, while C_WS, C_MB, C_P, C_L concentrations and CMI were significantly increased compared with the unfertilized control. In comparison with the control, the manure treatments, M and MNPK, significantly increased C_T content and C storage, sequestrating organic C of 8.9 and 9.2 Mg/ha, respectively. The M and MNPK treatments showed higher C_WS, C_MB, C_P and C_L concentrations and CMI than the other three treatments. Pearson’s correlation coefficients were used to show that C_WS, C_MB, C_P, C_L and CMI could be useful indicators for assessing soil quality and total C changes. The M treatment is effective in sequestrating soil C, but resulted in lower crop yield compared with the NPK treatment. The MNPK treatment showed the greatest increases in crop yield and C sequestration in the greenhouse vegetable system.     

不同生物有机肥用量对土壤活性有机质和酶活性的影响

通过盆栽试验研究了不同有机质含量的土壤中,不同用量生物有机肥对棉花苗期土壤活性有机质和5种酶活性的影响。结果表明,不同土壤随着生物有机肥施用量的增加,其活性有机质及碳库管理指数(CMI)均显著增加。其中高有机质含量土壤施用生物有机肥20 g/kg效果显著,中等有机质含量土壤和低有机质含量土壤施用生物有机肥30、40 g/kg效果显著。5种土壤酶活性施肥处理均高于对照(CK),并且土壤酶活性与施用量成正比。脲酶、蔗糖酶、多酚氧化酶在施用生物有机肥10、20 g/kg与其它处理相比变化显著,过氧化氢酶、蛋白酶变化不显著。相关分析表明,有机质与活性有机质和CMI在棉花出苗0 d相关系数分别为0.831**、0.542*;在出苗后60 d相关系数分别为0.928**、0.635**,其中有机质与活性有机质相关性最高。而CMI与有机质和活性有机质在棉花出苗0 d相关系数分别为0.542*、0.896**,在出苗后60 d分别为0.635**、0.842**,说明活性有机质相对于有机质与CMI关系更为密切。蔗糖酶、过氧化氢酶、多酚氧化酶与土壤有机质和活性有机质在棉花出苗0 d和出苗后60 d存在显著相关,表明活性有机质与土壤酶活性能够较好的反映肥力水平。     

有机肥在油-稻轮作田块对油菜生长和土壤肥力的影响

研究旨在探明油菜-水稻轮作制田块油菜季单施有机肥,油菜获得最高经济产量时田块有机肥的最佳施用量,为田块两熟制土壤培肥过程中采用有机肥在油菜季一次施用多年利用技术提供理论依据。试验在金华市蒋堂农业科学试验站进行,试验设:油菜、水稻不施肥对照处理(CK);油菜、水稻常规施化肥对照处理(CF);油菜施有机肥15 t/hm~2(T1)、30 t/hm~2(T2)、45 t/hm~2(T3)、60 t/hm~2(T4)、75 t/hm~2(T5),水稻均不施肥。共7个处理。结果表明,单施有机肥油菜经济产量最高,为2 300 kg/hm~2,比CK增产185%,比CF增产11.4%,油菜氮、磷、钾养分总吸收量最高,分别为87.2、34.7、146 kg/hm~2,分别比CK增加224%、427%、477%,分别比CF增加10.7%、230%、175%,以经济产量为依据,试验条件下油菜季单施有机肥的最佳施用量为60 t/hm~2;有机肥施用一年后,土壤pH值、有机质、全氮、全磷、全钾、碱解氮、有效磷、速效钾、阳离子交换量均不同程度增加,且有机肥用量达到60 t/hm~2后各肥力值与CK比较均达显著差异。     

不同耕作体系中施钾模式对作物产量的影响

Three patterns of potash application were used in the corn-wheat and rice-wheat rotation experiments,which were conducted in the upland and wetland of Siyang County,northern Jiangsu Provuince,and the wetland of Liyang City,southern Jiangsu Province.The results of 5 cropping seasons(2 seasons/year) showed that the direct response of corn to K was larger than that of wheat,but no difference was found between rice and wheat in Siyang when the total annual amount of K was applied only in one cropping season.However,the response of wheat was much greater than that of rice in Liyang.If potash was applied in the preceding season,the residual effect of K on wheat was larger than that on rice both in Siyang and Liyang,but less than that on corn,The total effect (direct and residual effects)of K applied to corn or rice was greater than that to wheat in Siyang,but that to wheat was greater in Liyang.The direct and total effects of K application in the upland were larger than those in the wetland of siyang;but fro the wetland,the effects were larger in Liyang than in Siyang,especially in the wheat season.The results demonstrated that the most profitable practice to be recommended to the local farmers was to apply a limited amount of potash to only rice or corn but not to wheat.Equally applying half of the total annual amout of K to each of the crops may be advisable in order to lessen possible fertilization risks.