ارزیابی شاخص‌های کارایی انرژی در نظام‌های زراعی حفاظتی مبتنی بر گندم (triticum aestivum l.) در شرایط اقلیمی منطقه معتدل (مطالعه موردی: گناباد)

این پژوهش به‌منظور ارزیابی تاثیر کشاورزی حفاظتی بر شاخص‌های انرژی در نظام‌های زراعی رایج با استفاده از طرح کرت‌های خرد شده در قالب بلوک‌های کامل تصادفی با سه تکرار در شرایط اقلیمی ایستگاه تحقیقات کشاورزی گناباد به‌مدت چهار سال ( 95-1391) مورد بررسی و ارزیابی قرار گرفت. فاکتورهای آزمایش عبارت بودند از سه سطح شیوه‌های مختلف خاک‌ورزی در کرت‌های اصلی شامل شیوه متداول خاک‌ورزی (شخم + دیسک + تسطیح + ایجاد فارو + کاشت با بذرکار)، شخم کاهش یافته (چیزل پکر یا دیسک سبک + ایجاد فارو + کاشت با بذرکار) و بدون شخم (کاشت مستقیم با بذرکار) و سه سطح مدیریت بقایای گیاهی شامل بدون بقایا، حفظ 30% بقایا و حفظ 60% بقایای گندم (triticum aestivum l.) که در کرت‌های فرعی قرار داشتند. این مطالعه در سیستم تناوبی رایج منطقه شامل گندم، جو، پنبه و گندم مورد برسی قرار گرفت. نتایج به‌دست آمده نشان داد که بیشترین مصرف انرژی از مقدار کل انرژی در تناوب رایج به نهاده‌های الکتریسیته، کودهای شیمیایی و سوخت به‌ترتیب با میانگین مصرف 43، 23 و 12 درصد و کمترین مقدار مصرف انرژی به نهاده نیروی انسانی با میانگین 7/0 درصد تعلق داشت. همچنین نتایج تجزیه واریانس و تحلیل‌های آماری شاخص‌های انرژی نشان داد که اثر شیوه خاک‌ورزی تنها بر شاخص کارایی مصرف انرژی برای دو محصول گندم و جو در سطح پنج درصد معنی‌دار بود. امّا اثر بقایا و اثر متقابل خاک‌ورزی و بقایا بر هیچ کدام از شاخص‌های انرژی معنی‌دار نبودند. مقایسه میانگین مقادیر شاخص‌ کارایی مصرف انرژی در تناوب مورد نظر نشان داد که بیشترین و کمترین مقدار این شاخص به‌ترتیب در دو شیوه بدون خاک‌ورزی یا کشت مستقیم و خاک‌ورزی متداول مشاهده شد، به‌نحوی که میانگین شاخص کارایی مصرف انرژی برای دو محصول گندم و جو در شیوه بدون خاک‌ورزی به‌ترتیب 21 و 9 درصد افزایش را نسبت به خاک‌ورزی متداول و خاک‌ورزی کاهش یافته نشان داد.

Evaluation of Energy Efficiency Indices According to Wheat (Triticum aestivum L.) based Crop in Conservation Agricultural Systems in Temperate Climate Region (A Case Study: Gonabad)

IntroductionThe relation between agriculture and energy is very tight. Agriculture itself is an energy user and energy supplier in the form of bioenergy. Energy consumption in agriculture has intensified in response to increasing populations, limited supply of arable land and desire for an increasing standard of living. In all societies, these factors have encouraged an increase in energy inputs to maximize yields, minimize laborintensive practices, or both. Effective use of energy is one of the conditions for sustainable agricultural production, since it provides financial savings, fossil resources preservation and air pollution reduction. In developing countries, agricultural growth is essential to fostering economic development. In Iranian economy, more than 33% of the total population is engaged in agriculture sector.  Recent years with the rise in world energy prices the governments has taken steps to reduce fuel and energy consumption. Energy in agricultural sector  are divided into two groups of direct and indirect, direct energy is required to perform various tasks related to crop production processes such as land preparation, irrigation, threshing, harvesting and transportation of outputs. Indirect energy consists of the energy used in the manufacture of fertilizers, seeds, herbicides and farm machinery and so on. Recently, application of integrated production methods are recently considered as a means to reduce production costs, to efficiently use human labor and other inputs and to protect the environment.Material and MethodsThis research was carried out to evaluate the effect of conservation agriculture system on energy indices in conventional rotation systems including wheat, barley and cotton. The experiment was conducted at Gonabad Research Station as a moderate climate condition between 2012 and 2016 by using split plot design in a randomized complete block design (CBD) with three replications. Two substantial criteria were investigated such as different tillage methods including conventional plowing, reduction of tillage (Minimum tillage) and direct cultivation (No tillage) as a main plots, as well asamount crop residue involving absence of residues 30 and 60%of the remains as a subplots. The area for each subplot and main plot was 600 and 1800 m2, respectively. In this study, energy indices were calculated using equations .Besides, data analysis and mean comparisons were performed via SAS (SAS, 2002) software and Duncan test, respectively.Result and DiscussionAccording to results, electricity, chemical fertilizers and fuel inputs shared the highest energy consumption from the total amount of energy in the conventional crop rotation with 43, 23 and 12%, respectively. On the other hand, the lowest energy consumption related to the input of human resources with an average of 0.7%. In addition, variance evaluation and statistical analysis of energy indices demonstrated that only energy efficiency index for wheat and barley at level (p≤0.05) dramatically affected by tillage methods. . However, the effect of residues and interaction between soil tillage × residues on other energy indices was not significant. Comparison of average values ​​of energy use efficiency index in the conventional rotation illustrated that the highest and lowest values ​​of this index were observed in two methods without soil tillage or direct planting and soil tillage or customary tillage. Therefore, the average of energy use efficiency index for wheat and barley crops in nontillage method was represented increasing 21 and 9%, respectively, than that of conventional tillage and minimum tillage methods.ConclusionConsequently, based on data analysis, it seems that the implementation of conservation agricultural systems with various tillage procedures (non – tillage or minimum tillage) to enhane energy use efficiency is exclusively recommended for wheat and barley agronomic systems in climate condition of this study.