Effects of Nitrogen on Dry Matter Accumulation and Productivity of Three Cropping Systems and Residual Effects on Wheat in Deep Vertisols of Central India

A field experiment was conducted on deep vertisols of Bhopal, India to study the effects of three levels of nitrogen (N), namely 0, 75 and 100 % of the recommended dose of nitrogen (RDN), on the dry matter accumulation (DMA) and productivity of three cropping systems (sole soybean, sole sorghum and soybean + sorghum intercropping) during the rainy season and their residual effect on the subsequent wheat crop during the post-rainy season. During the rainy season, sole sorghum was found to have significantly higher DMA and productivity in terms of soybean equivalent yield (SEY) than sole soybean or soybean + sorghum intercropping. Increasing the N dose from 0 to 100 % RDN significantly improved the DMA and SEY. At a low fertility level (N₀), soybean + sorghum intercropping was found to be more productive, while at a high fertility level (100 % RDN), sole sorghum was more productive than the other two cropping systems. However, during the post-rainy season, sole soybean as the preceding crop gave the highest DMA and seed yield of wheat, which were similar to those found with soybean + sorghum intercropping. Sorghum followed by wheat gave the lowest DMA and seed yield of wheat. Application of 100 % RDN irrespective of cropping system during the preceding crop improved the DMA of wheat but not its seed yield. However, N applied to the wheat crop significantly increased its DMA and seed yield.     

Productivity and Sustainability of Cotton (Gossypium hirsutum L.)–Wheat (Triticum aestivum L.) Cropping System as Influenced by Prilled Urea, Farmyard Manure and Azotobacter

Field experiments were conducted at Indian Agricultural Research Institute, New Delhi, during 2001–2002 and 2002–2003, to study the effect of inorganic, organic and Azotobacter combined sources of N on cotton (Gossypium hirsutum L.) and their residual effect on succeeding wheat (Triticum aestivum L.) crop. The results indicated considerable increase in yield attributes and mean seed cotton yield (2.33 Mg ha^?1) with the combined application of 30 kg N and farmyard manure (FYM) at 12 Mg ha^?1 along with Azotobacter (M₄). The treatment in cotton that included FYM, especially when fertilizer N was also applied could either improve or maintain the soil fertility status in terms of available N, P and K. Distinct increase in yield attributes and grain yield of wheat was observed with the residual effect of integrated application of 30 kg N ha^?1 + FYM at 12 Mg ha^?1 + Azotobacter. Direct application of 120 kg N ha^?1 resulted 67.4 and 17.7 % increase in mean grain yield of wheat over no N and 60 kg N ha^?1, respectively. Integrated application of organic and inorganic fertilizer is therefore, recommended for higher productivity and sustainability of the cotton–wheat system.     

连作和轮作对谷子叶片构型和叶绿素、氮素含量的影响

研究旨在提升谷子连作障碍认知度,为谷子轮作制度和可持续生产提供理论依据和技术支持。采用周年单序轮作处理和连作处理相比较的方法,研究其对旱地谷子叶片构型、叶绿素和氮素含量的影响。结果表明,连作处理降低谷子个体的叶面积和群体的叶面积指数,严重影响谷子叶片的生长发育;降低谷子叶片的叶绿素和氮素含量,影响谷子叶绿体的发育。谷子连作种植是不科学的田间生产方式,应选择合理的年际轮作制度,以实现谷子高产稳产。     

江苏种养结合猪场粪污处理典型模式分析Ⅰ——政府主导型

总结归纳江苏养殖粪污处理典型模式,为区域尺度发展种养结合循环农业,实现农业废弃物资源化统筹协调高效利用,提供模式参考及案件借鉴。以政府主导型的武进区农业废弃物综合治理中心（礼嘉站）为例,介绍种养结合模式背景及构架,分析关键技术组成,剖析经济、生态及社会效益,阐明运行机制。结果表明：收集分散服务体系建设形成了养殖业、种植业、第三方服务组织、政府及社会群众之间的利益共同体,破解了小型养殖粪污无害化处理与资源化利用的瓶颈难题,促进了“乡村振兴”的“环境美、农民富”进程。江苏探索的政府主导型养殖粪污集中处理模式,对构建和发展区域尺度种养结合循环农业更具代表性及示范价值。     

减量施肥模式对稻麦轮作体系中小麦产量和养分利用效率的影响

为实现化肥高效施用和零增长目标,采用稻麦轮作定位大田试验,探讨不同减量施肥模式对轮作体系小麦产量及养分利用效率的影响。设置不施肥（T1）、常规化肥（T2）、等养分条件下有机肥与化肥配施（T3）、T3减N 20%+氮增效剂（T4）、T3减P 20%+磷素活化剂（T5）及T3减N、P各20%+氮增效剂+磷素活化剂（T6）6个处理。结果表明,与T2处理相比,各减量施肥处理对稻麦轮作体系小麦产量影响不显著,T4处理3年平均产投比提高3.96%,T5和T6处理分别降低59.21%和56.24%;T4处理氮素吸收效率、氮素利用效率和钾素利用效率分别提高9.22%~20.70%、7.01%~28.67%和4.69%~7.67%;T5处理小麦磷素总吸收量、吸收效率、偏生产力和利用效率分别提高15.53%、21.43%~46.67%、12.18%~52.06%和3.77%~4.52%;T6处理氮素吸收效率、磷素偏生产力和钾素利用效率分别提高5.67%~19.40%、10.88%~43.43%和7.38%~12.97%;T3处理对小麦氮、磷素的吸收与利用均无显著影响,但显著降低了小麦钾素偏生产力。综合结果表明,T6处理可稳定小麦产量,有利于协调作物养分吸收,但磷素活化剂使用成本高,经济效益偏低。     

Effect of Soil Moisture on Relative Leaf Water Content, Chlorophyll, Proline and Sugar Accumulation in Wheat

The responses of four wheat ( Triticum aestivum L.) varieties to soil moisture were determined by measuring plant parameters such as relative leaf water content (RLWC) and the chlorophyll, proline and sugar contents of the leaf over two seasons. Two levels of irrigation treatments were adopted: irrigated and rainfed. The rainfed plants had consistently higher amounts of proline and sugar but lower RLWC and chlorophyll content. As drought intensified, differences between the irrigated and the rainfed plants with respect to all of these characters increased. The RLWC values of the irrigated plants were significantly higher in the morning but lower values were found at noon, showing some recovery in the afternoon.     

Effects of Cropping System, Seed Bed Management and Fertility Interactions on Biomass of Crops Grown on a Vertisol in the Central Highlands of Ethiopia

In the Ethiopian highlands, where integrated crop and livestock production takes place, the inadequate supply, in both quantity and quality, of feeds during the year is a major constraint. Native pastures and crop residues are the major feed sources, but their quality is often poor. Integration of forage legumes in the cropping system is one alternative to improve the fodder quality. Results of field work conducted over two seasons in order to assess and evaluate the potential yields of crops, crop/forage combinations and rotation systems on a Vertisol under two seed bed preparation systems showed that intercropping wheat with clover or sequential cropping of an oat/vetch mixture followed by chickpea provided high-quality fodder; the effect was greater under fertilized conditions. In addition, where monocropping treatment was tested, legume–cereal rotation resulted in higher grain and fodder yield when compared to cereal–cereal rotation. The study also showed that two short-duration crops could be produced in sequence per year. It is therefore suggested that the Vertisols in the Ethiopian highlands could provide a good opportunity for longer period cropping using improved food and forage crops, thereby improving the availability and quality of animal feed and protecting the land against erosion.     

施肥及光合调节剂对小麦根系及籽粒产量和蛋白质含量的影响

以在施肥总量相同条件下不同底施和追施比例及光合调节剂的处理，研究了小麦不同时期根系特征及籽粒产量和蛋白质含量。结果表明：氮肥全部底施和提高底施比例有利于增加拔节期和孕穗期的根长密度、根平均直径和根总表面积。各种氮肥处理上述根系特征指标在各土层中均表现为孕穗期比拔节初期数值大。增加追施氮肥的比例有利于     

麦季氮肥运筹对冬小麦–夏玉米种植体系物质生产及氮肥利用的影响

2009-2011年在山东临沂冬小麦-夏玉米生产田,探讨了麦季施氮水平和施氮时期对两季作物干物质积累与分配、籽粒产量、氮肥农学利用率和氮肥偏生产力的影响。施氮量设4个处理,分别是0 (N0)、168.75 (N1)、225 (N2)和281.25 kg hm^-2 (N3);氮肥追施时期设2个处理,分别为拔节期(S1)和拔节期+开花期(S2)。在S1条件下,冬小麦和夏玉米的籽粒干物质积累量及夏玉米和周年生物产量均表现为N3>N2>N1,冬小麦和夏玉米的籽粒产量N2和N3处理间无显著差异;氮肥农学利用率和氮肥偏生产力在麦季随施氮量增加显著降低,而在玉米季则逐渐升高,但玉米季氮肥偏生产力N3与N2处理间无显著差异。S2条件下麦季施氮量由N2处理增加25% (N3),冬小麦和夏玉米籽粒干物质积累量、生物产量和籽粒产量无显著变化,氮肥农学利用率和氮肥偏生产力在麦季显著降低、在玉米季无显著变化。与S1相比,S2有利于提高N1和N2条件下冬小麦籽粒与营养器官的干物质积累量、生物产量、籽粒产量和氮肥农学利用率及氮肥偏生产力,但对N3条件下的这些指标无显著影响;而在玉米季,3个施氮量水平下夏玉米的各项指标均显著升高。综合周年生物产量、籽粒产量和氮肥农学利用率及氮肥偏生产力结果,麦季总施氮量225 kg hm^-2及拔节期+开花期追氮是本试验条件和种植模式下的最佳麦季氮肥运筹模式。     

Effect of Nitrogen Rate and Stubble Height on Dry Matter Yield,Crude Protein Content and Crude Protein Yield of a Sorghum–Sudangrass Hybrid[Sorghum bicolor (L.) Moench × Sorghum sudanense (Piper) Stapf.] in the Three‐Cutting System

In this study, the effects of nitrogen (N) rate (60, 120, 180 and 240 kg N ha^?1 applied in three equal dressings at seeding and after the first and second cuttings) and stubble height (7, 14 and 21 cm) on the dry matter (DM) yield, crude protein (CP) content, and CP yield of a sorghum–sudangrass hybrid [Sorghum bicolor (L.) Moench × Sorghum sudanense (Piper) Stapf., cv. Pioneer 988] in the three‐cut system was investigated. The N rate had no significant effect in the first and third cuttings, but in the second cutting DM yields increased significantly with increase in N rate. The highest yield of 9.1 t ha^?1 was obtained with 80 kg N ha^?1 for the average of 2 years at the second cutting, but no significant difference was found among the 40, 60 and 80 kg N ha^?1 rates. CP content and yield were not significantly affected by N rate at the first and third cuttings, but CP content and yield were significantly affected by application of N at the second cutting. Stubble height had a significant effect on CP content at the third cutting. However, it had no significant effect on CP content at the first and second cuttings. Stubble height had a significant effect on the CP yield at the first cutting, but no significant effect on CP yield at the second and third cuttings.