جستجوی مقالات مرتبط با کلیدواژه "شبدر برسیم" در نشریات گروه "اکولوژی"

This study was performed to investigate the effect of nitrogen fertilizer levels and pre-planting of cover crops on some vegetative traits and yield of rice plants.

This was conducted over 2017-2018 and 2018-2019, at the research farm of Sari University of Agricultural Sciences and Natural Resources. The experimental design employed a three-replicated split-plot arrangement within a randomized complete block design. The main plots involved five nitrogen consumption levels (0, 120, 240, 320, and 400 kg ha-1). The sub-plots included four types of pre-planted cover crops (no cover crop, canola, bersim clover, and rye).

Based on the findings, employing berseem clover as a cover crop in pre-sowing resulted in a significantly more favorable rice yield than others. Nitrogen fertilizer at rates of 320- 400 kg ha-1 led to enhanced vegetative traits, yield, and various yield components, including leaf area index and tiller number, ultimately resulting in increased overall yield. Results revealed that planting bersim clover cover crop before planting rice, along with 320 kg ha-1 of urea fertilizer, leads to 41.5% higher yield compared to no fertilizer).).

Bersim clover stood out among the pre-planting cover crops, significantly enhancing many rice traits. Additionally, no significant difference was observed between urea fertilizer levels of 320 and 400 kg ha-1 in several measured traits. Thus, the integrated treatment of bersim clover cover crop and 320 kg ha-1 of urea fertilizer is recommended before planting rice.

Cultivation of cover crops associated with their proper management can be a sustainable alternative to conventional weed control methods. In addition to their beneficial effects on weed control, these plants can improve soil structure and organic matter, increase water holding capacity, control soil-borne diseases, reduce soil erosion, and subsequently enhance crop yields. The use of suitable cover crops and optimizing the planting date can improve the advantages mentioned above, especially desired weeds control. They were considering the importance of sunflower production development and the need to introduce the ecological approaches in weed control; the present study aimed to investigate the efficiency of some cover crops and their optimum planting date, the influence on weed structure population and morphological traits, and sunflower seed yield (cv. Lakumka) under climatic conditions of Galougah city, Mazandaran province.

In order to study some cover crops and their optimum planting date on controlling the weeds in sunflower production, an experiment was conducted in Galoogah city (Mazandaran province, Iran) based on a factorial split-plot arranged in a randomized complete block design (RCBD) with four replications during two growing seasons (including 2016-2017 and 2017-2018). Experimental treatments were considered to cover crops such as wheat, barley, berseem clover, hairy vetch, and different planting dates, including planting two months before, simultaneous, and two weeks after the sunflower planting. Moreover, two treatments without any cover crop cultivations, including with and without weeding, were designed as controls.

The study results revealed that the cultivation of mentioned cover crops, regardless of types and planting dates, had a significant role in weeds control and increasing the seed yield of sunflower. In all treatments, the highest weeds dry matter was observed two months before the sunflower planting treatment. Also, barley cover crop had the lowest weeds dry matter in both experimental years in two months before the sunflower planting. It could maintain the weeds dry matter lower than other cover crops during various stages of sunflower growth. The lowest weed dry matter was observed in simultaneous planting with sunflower for all cover crops. Planting cover crops two weeks after sunflower planting also reduced the weeds dry matter. However, its efficiency was lower than the simultaneous planting of cover crops with sunflower. The highest and lowest sunflower height were observed in the treatments of berseem clover at the same time of planting and in wheat cover crop planting two months before planting of sunflower (181.76 and 105.98 cm), respectively. The highest leaf area index (3.97) was related to berseem clover cover crop in simultaneous planting date with sunflower, which was 14 and 69% more than control treatment without covering crops in weeding non-wedding conditions in two years of experiment, respectively. The lowest sunflower leaf area index was obtained from the wheat cover crop on the planting date two months before sunflower planting (first and second year 0.96 and 1.08, respectively). The highest sunflower dry matter (485.61 g.m-2) was observed in berseem clover cover crop simultaneous with sunflower planting, which was not significantly different from control treatment in weeding conditions. The lowest sunflower dry matter (108.27 g.m-2) was obtained in wheat planting two months before sunflower planting. Finally, the highest seed yield of sunflower was obtained in simultaneous planting of berseem clover with sunflower (2859.06 kg.ha-1), which was 17% higher than the control treatment without any cover crops in weeding condition (2381.1 kg.ha-1).

Simultaneous planting dates of cover crops with sunflower led to seed yield similar to weeding treatment. Even planting of berseem clover and hairy vetch had 17 and 14% enhancement in sunflower seed yield. Therefore, berseem clover cover crop planting simultaneously as sunflower planting, reduced weed growth, and increased seed yield of sunflower, it can be introduced as a solution for optimal sunflower production in sustainable agriculture.

Application of nitrogen fertilizers is one the main practices to increase the yield of agricultural products. However, the addition of high and unbalance amount of fertilizers led to negative consequences on the environment, reduction of fertilizer use efficiency and increase cost of production. Crop rotation is one of the most effective methods to increase nitrogen efficiency at agricultural ecosystems, stated that type of planted crop in previous years can alter soil condition and hence enhance the yield of the next crop. Recent studies revealed that crop rotation alone is not capable of providing required nutrients for plant growth. Hence, if uptake nutrients by plants were not recycled, the crop rotation system would not fully beneficial. Therefore, incorporation of crop rotation and fertilization could be considered as a suitable solution to have stable and high-quality crop yield with environmental protection. Based on stated notes, this experiment was conducted to find the most effective nitrogen fertilizer level and reduction of fertilizer use in Purslane farms by crop rotation.

This experiment was conducted with factorial split plot based on randomized complete block design with three replications at Ramin Agriculture and Natural Resources University of Khuzestan during 2012-2013. Nitrogen fertilizer (Urea) was at five levels: (N1-Control, N2-75kg.ha-1, N3-100 kg.ha-1, N4-125kg.ha-1 andN5-150kg.ha-1. Two preceding plants P1- Wheat, P2-Bersim Clover and cutting (C) was placed at sub plot. Plant cutting of Purslane was done in two times. Anova performed by SAS 9.1 and means were compared by (LSD) at the error probability of 0.05%.

Results of the experiment showed that plant height was affected by the amount of applied fertilizer rate. The increase in fertilizer rate led to more plant height. The first cutting, stem diameter was increased by higher fertilizer rate and the highest stem diameter (5.41 cm) was achieved at 125 kg N.ha-1. At the second cutting, there was no significant difference among fertilizer treatments. First and second cutting the value of chlorophyll in bersim increased and the highest value was observed in 150 kg N. ha-1. At first cutting, little difference between 150 kg N × wheat and 150 kgN × clover on the fresh and dry weight leaves of purslane was observed. But in second cutting, the highest fresh and dry weight leaves was observed in the high level of nitrogen × clover.The increase in fertilizer rate was led to a higher dry weight of Purslane due to increase in stem length, a number of leaves and fresh and dry weight of leaf. The highest fresh weight (26.34 g.plant-1) belonged to 150 kg N and bersimpreceding at the second cutting. Plant dry weight showed that maximum plant dry weight was at the first cutting with 125 kg N and bersimpreceding which showed no significant difference of 150 kgN.ha-1. Results showed that the first and second cutting had the higher leaf protein with 12.61 and 14.43 % for bersimpreceding and 150 kg N.ha-1 treatments.

Based on results of this experiment, it is stated that response of Purslane to preceding is different and cutting legume plant as preceding could improve physio-chemical properties of soil and increase the crop yield. The response of Purslane to preceding and fertilizer treatment was different. Application of 125 kg N.ha-1 with berismpreceding could produce equal or higher yields compare to 150 kg N.ha-1. Application of higher nitrogen led to more watery stem plants and higher plant weight. Generally, due to the medicinal application of this plant, application of suitable crop rotation and optimization of nitrogen fertilizer in a rotational system with preservation of soil fertility, environmental protection, water quality and biodiversity could increase input efficiency and enhance crop quality.

In recent decades, a new agricultural system known as ‘conservation agriculture’ was introduced to the world as a progressive solution for such challenges as soil erosion, environmental problems and the low input efficiency of energy, water and fertilizer that the conventional agriculture system is exposed to (Rolf Derpsch and Friedrich, 2009; Cavalaris and Gemtos, 2002; Romaneckas et al., 2009). In Iran, comprehensive studies covering all principles of conservation agriculture system have not been conducted. This research was undertaken in order to study the adaptation of the conservation agriculture system to the agricultural conditions of cold regions of Khorasan-Razavi Province and its effects on different crop yields to identify whether reducing tillage practice and preserving crop residue positively affect crop yield.
In order to study the effects of tillage method and residue amount on crop yield, an experiment with a split plot layout based on a randomized complete block design (RCBD) with three replications was conducted at the Jolg-e-Rokh Station of Khorasan-Razavi Agricultural and Natural Resources Research and Education Centre (59°E and 35°, 50´N) during two growing seasons (2013-2014). In this experiment, tillage methods were applied in main plots at three levels, namely (1) conventional tillage (mouldboard plough 2 times disc levelling planting with seeder), (2) minimum tillage (2 times chisel packer planting with seeder) and (3) no tillage (direct planting with a notill seeder). The residue amount was in a sub plot at 3 levels, namely no residue, 2- 30% residue and 3-60% residue of the previous crop.
Results showed that in Bersim clover, change in the tillage system reduced (P It seems that the use of a no-tillage instead of a conventional tillage method, especially when preserving residue, can obtain the same or higher yield in clover and sugar beet.

Application of living mulch and stale seedbed has been proposed for weed management in crop production. Field experiment was carried out at the Research Farm of university of Zanjan in 2013 as split block based on randomized complete block design to assess integration of living mulch and stale seedbed for weed management in maize. The main plot was stale seedbed preparation (6 April, 3 May, and 24 May), and sub plot three different living mulch included Vicia villosa, Trifolium alexandrinum, and Lathyrus sativus. Cover crops were planted in the space between two rows at the recommended densities. Weed free and weed infestation, were also included. The results showed that 100-seed weight, biomass and seed yield of maize significantly affected by the time of stale seedbed preparation. However, this treatment had no effect on traits such as plant height, ear diameter, seed row number per ear and weed biomass. The highest maize grain yield (8.7 t.ha-1) was obtained when seedbed prepared on 6 April. Living mulch had significant effects on maize and weed growth. The highest maize grain yield was obtained in weed free plots. The lower weed biomass was produced when T. alexandrinum was used as a cover crop. The interaction of the stale seed bed and living mulch was not significant. These results suggest that living mulch or stale seedbed alone or in combination could not provide reliable weed control in maize; therefore, these methods should be integrated with other efficient weed control measures.

The vertical distribution of leaf area and dry matter is considered to be an impact factor on light absorption, evapotranspiration of canopy, dry matter accumulation and seed yield. To study the vertical distribution of leaf area and dry matter of the maize canopy in competition with weeds and cover crops, an experiment was conducted at Sari in 2011. This experiment was performed in a randomized complete block design with 8 treatments and three replications. Three cover crops, namely bean (Phaseolus vulgaris), soybean (Glycine max L.) and berseem clover (Trifolium alexandrium), were planted on two dates: simultaneous with and 21 days after maize sowing (delayed planting). In addition, maize sole crop with weed control and weed interference was added to the treatments. The results showed that dry matter and leaf area index of bean and soybean were higher than for clover. The delayed planting of bean and soybean increased the leaf area index of maize upper layer canopy rather than sole cropping of maize with weed interference: this approach caused an increase in the competitive ability of maize against weeds. The leaf area and dry matter of weeds were reduced more by bean and soybean than by berseem clover. The cover crops caused the maximum amount of weed (in particular, veveltleaf and bermuda grass) dry matter to be accumulated in the primary layer. The cover crops reduced the number of layers and dry matter of per layers in the weed canopy. For maize, the dry matter was less in the presence of berseem clover than for the two other cover crops. The maximum amount of weed dry matter was accumulated in the primary layer. Grain yield in maize was higher in simultaneous sowing than in delayed planting of cover crops, especially soybean. The cover crops’ dry matter had a positive correlation with dry matter of maize and was negatively correlated with dry matter of weeds. The yield of maize in the present of crop cover was higher than for sole cropping of maize under weed interference. The grain yield of maize with a delayed presence of cover crop was higher than at the same sowing date.