ارزیابی اقتصادی تناوب‏های زراعی در کشاورزی حفاظتی منطقه معتدل سرد مشهد

این مطالعه با هدف ارزیابی اقتصادی دو تناوب زراعی و در قالب کشاورزی حفاظتی انجام شد. آزمایش‏های هر تناوب زراعی با استفاده از طرح کرت‏های خرد شده در قالب طرح بلوک های کامل تصادفی و با سه تکرار، در ایستگاه تحقیقات کشاورزی و منابع طبیعی استان خراسان رضوی در 5 سال متوالی انجام شد. تیمارهای آزمایش، شیوه‏های مختلف خاک ورزی در سه سطح شامل: شیوه متداول خاک‏ورز ی (شخم + دیسک + تسطیح + کاشت با بذرکار)، شخم کاهش یافته (چیزل پکر یا دیسک سبک + کاشت با بذرکار) و بدون شخم (کاشت مستقیم با بذرکار) در کرت های اصلی و مدیریت بقایای گیاهی در سه سطح بدون بقایا، حفظ 30% بقایا و حفظ 60% بقایای محصولات مختلف درکرت‏های فرعی قرار داده شدند. سیستم تناوب زراعی رایج این منطقه شامل گندم (triticum aestivum l.) ذرت (zea mays l.) گندم خربزه (cucumis  melo l.) گندم و سیستم تناوب زراعی پیشنهادی یا پایدار شامل گندم کلزا (brassica napus l.)گندمشبدر ایرانی (trifolium resupinatum l.) گوجه‏فرنگی (solanum lycopersicum l.) گندم هر کدام بصورت جداگانه با استفاده از روش بودجه‌بندی جزئی مورد بررسی اقتصادی قرار گرفت. اطلاعات مورد نیاز شامل میزان و ارزش نهاده‏های استفاده شده در مراحل کاشت، داشت، برداشت و محصولات حاصل شامل محصول اصلی و کاه و کلش بود. نتایج نشان داد که منفعت خالص تناوب پایدار در مجموع، بیش از دو برابر منفعت خالص تناوب رایج است. در تناوب زراعی رایج تیمار شخم متداول با حفظ 30% بقایای گیاهی با منفعت خالص 246371580 ریال و نرخ بازده 437 درصد بیشترین منفعت خالص و نرخ بازده را داشت. در صورتی‌که در نظام تناوب زراعی پایدار تیمار بدون شخم و بدون بقایا با منفعت خالص 450020790 ریال بیشترین درآمد و کمترین هزینه را داشت. خالص ارزش تولید هر متر مکعب آب در تناوب پایدار 56159 ریال و در تناوب جاری 27157 ریال بود. این نتایج نشان داد، تناوب زراعی که کشاورزان استفاده می‏کنند از نظر اقتصادی توجیهی برای بکارگیری کشاورزی حفاظتی ندارد، اما اگر تناوب زراعی تغییر کند در آن صورت کشاورزی حفاظتی در قسمت حذف ماشین‏آلات آماده سازی زمین، اقتصادی است، اما تمایلی به حفظ بقایا ندارد.

Economic Evaluation of Crop Rotations in Conservation Agriculture System in Temperatecold Climatic Zone of Mashhad

Introduction; Tillage and preparation of soil, alone account for a significant part of the crop production costs, which according to statistic of Ministry of JihadeAgriculture in 2015, about 9% of the total cost per hectare of wheat (28 million Riyal) has been allocated to plowing and discs. Therefore, in order to reduce costs, energy consumption, equipment depreciation, saving during operation, maintaining the environment and sustainability of the production system, the approach to low tillage and no tillage has grown further. However, the development of these methods is accompanied by barriers that can be largely categorized into three broad categories: access to machinery, social barriers and economic issues. Farmers are worried that reducing the income resulting from the elimination of some inputs, especially tillage is more than reducing its costs. Here are two points that affect farmers ' decisionmaking: One is which crop rotation is sustainable for sustainable farming? And the other is which sustainable crop rotation, can serve the economic interests of farmers? The past studies have shown that in agronomic rotations, because of the variety of products, it is necessary to evaluate the treatments in order to select the best alternatives. In addition, in conservation methods, reducing production costs cannot be a reason for the superiority of treatments with minimum tillage and it is necessary to evaluate these treatments economically.;  ;Material and methods; This research was carried out with the aim of evaluating the economic efficiency of conservation agricultural system and comparing it with conventional agricultural practice in two crop rotations include conventional and sustainable systems. Experiments were conducted using a splitplot design based on randomized complete block with three replications in research station of Torogh Mashhad during 201116 growing seasons. Main factor was three tillage methods include 1Conventional Tillage: Plow + Disc + Leveling + Faro + Seed planter, (CT), 2Reduced Tillage : Disc +Faro + Seed planter, (RT) and 3No Tillage: direct plant by Seed planter (NT)) were allocated in main plots and three residue management (Zero (R0), 30% (R1) and 60% (R2) of residue retention) were assigned in sub plots. Experimental treatments were compared and valuated  by using partial budgeting method.  ;Results and discussion; Results showed that sustainable crop rotation, SCR, has a higher overall production value than conventional crop rotation, CCR,. The ratio of the production value of SCR to CCR is between 1.64 to 2.1 and 1.8 on average, and the ratio of costs is almost 1.08, but the net profit ratio of SCR to CCR is from 1.9 to 2.6 and 2.1on average. However, the difference between cost of two crop rotation is almost 8%, but the difference in their water consumption is 3% (71400 cubic meters in the CCR versus 73695 cubic meters in the SCR), in other words, in the SCR The value of production per cubic meter is 56159 Rials, in the event that in the CCR is 27157 Rials. Increasing tillage, increase the benefit of treatments. Nevertheless, increasing in residue retention in NT, decrease benefit. Although, in RT and CT increasing in residue retention to R1 increase and to R2 decrease benefit. Therefore, in RT and CT, economical treatment is R1. In the CCR, the highest net income and rate of return treatment was CT + R1. In the event that in SCR, the highest income and the lowest cost treatment was NT + R0. In the CCR, the treatment of CT + R1, with the net benefit of 246371580 Rials and a rate of return, ROR, 437%, had the highest net benefit and ROR. In the event that in the SCR, the treatment of NT + R0, with the net benefit of 450020790 Rials had the highest income and the lowest cost. These results indicate that applying conservation agriculture in the CCR isn’t economical. But if the crop rotation changes, then the conservation agriculture in the field of no tillage is economical, and isn’t for residue retention.  ConclusionResults showed that SCR has a higher overall production value than CCR. In the CCR, the highest net income and rate of return treatment was CT + R1. In the event that in SCR, the highest income and the lowest cost treatment was NT + R0.