Abstract
Pinto bean is a popular plant in the United States and Mexico, so knowing how it grows is an important topic in the field of botany. One of the factors that influence plant growth is the soil condition in which the seeds are planted on. Based from the many studies conducted on pinto bean, as well as soil condition and plant growth, the amount of water in the soil is an important factor in the quality and production rate of the plant. Lack of water can negatively impact the growth of pinto bean, but some varieties of the plant can manage to adapt to long periods of drought. Additionally, the nutritional content of the soil affects the growth of the plant. The soil temperature, which affects how rich the plant is, also is a major determinant in the growth of the pinto bean. Cobalt, an element that supports plant growth but otherwise considered nonessential, affects also the pinto beans but also to an extent—too much will have a negative impact on the plant. Phosphorus, being a primary element of the soil, can affect the growth of the plant to a major extent. Lastly, soil type, which helps determine permeability, is also a determining factor. Accordingly, like any other plants, pinto beans grow best in loamy soil. The methods of data analyses used by the reviewed studies allow the improvement the reliability of their respective findings, which can serve as foundations for future studies.
Keywords: pinto bean, soil content, water, drought, nutritional contents, soil type
REVIEW OF RELATED LITERATURE
Introduction
Pinto beans (Scientific name: Phaesolus vulgaris) is a variety of a common bean that is popular in the United States and Mexico. They are usually distinguished by their beige color speckled with shades of reddish brown; in fact, its name comes from the Spanish word “pinto” meaning “painted”, referring to its unique appearance. It can be prepared in a variety of ways, such as eating it whole in broth, mashing it, and refrying it. Pinto beans are also commonly used as fillings in burritos. The pods of the plant can also be used and eaten as green pinto beans. According to Camara’s research which focused on the nutritional qualities of the pinto beans (2013), pinto beans are low in saturated fat and high in protein, making it an ideal meal.
Because of the popularity of the plant, one particular interest in the field of science is to determine in what factors will the pinto bean plant will grow best. Plant growth is a very important topic in botany. There are many factors that influence and growth rate of a plant, and these factors differ from plant to plant. What conditions are ideal for one species of plant may not be necessarily the same for another plant, especially when the plants thrive in different climates. Therefore, botanists are interested in knowing what factors in which a plant will grow best so that this information can be used in agriculture.
One particular condition that is crucial for a plant to grow is the soil condition. Soil condition refers to the characteristics of the soil wherein the plant will grow. Different types of soil have varying amounts of nutrients and minerals, and can hold different amounts of water and oxygen based on their textures and particles. Clay has the finest particles, but roots may not be able to hold on tight to them. Sandy soil has the largest particles, but they are usually not fertile. Loam is the ideal soil type; it can be dug enough easily but can hold plants and is usually fertile. The fertility of soil refers to the nutrients in the soil and can be improved by putting fertilizer to make plants grow better. A study by Gill et al (2014) showed that clay sail is stronger, but suffers from drawback such as waterlogging. They tested different types of soil and compared the results of each. This study provides a deep knowledge on the effects of soil on plant growth.
Many studies have been conducted about the pinto bean, soil conditions necessary for plants to grow, and the like. Reviewing these pertinent studies can give insight to the nature of the pinto bean as a whole as well as provide a hypothesis on the possible result of the research question.
Plant Growth and Soil Content: A General Overview
Before delving on the effect of soil conditions on the pinto bean itself, it may be first be necessary to focus on a general overview on the effects of soil condition to plants. Passioura (2002) conducted a study on how plants can react to certain environmental conditions. Generally, a plant will adapt to the environment it is placed in, but the effect on it on the growth of the plant in question may vary. For example, a soft soil may force roots to grow larger but the stomatal response of the plant would be slow. He concluded that there is a network of hormones that regulate the plant growth in general, and it is largely affected by the environmental conditions that the plant is subjected to. Some parts of the research done is unclear and needs more investigation, but it provides a sufficient overview of plants in general.
One important soil condition is the water content, or the lack thereof. The effect of drought on plants is analyzed in the study by Whitmore and Whalley (2009). Like in the above, it is theorized that the response of the plants in the environmental conditions may explain its behavior on certain conditions. They also cited other environmental factors, which can suggest the fact that there is no one factor that can explain adequately the effect of soil conditions in the growth of plants. This can prove to be logical; as environmental factors are interrelated, it can be theorized that its effect on plants are caused by many other factors as well.
The effect of soil types on plant growth can be found in Ayalew’s study published in 2014. Here, the effect of the soil type on the growth of certain plants was analyzed using randomized complete block design, and determining attributes of life such as number of leaves, leaf growth, height, and the like. The results showed that plants perform better at pot soil compared to sandy soil. The use of a credible scientific method makes this research verifiable, but whether the results are applicable to the pinto bean is still unknown.
Pinto Beans, Soil Moisture and Drought Stress
There are many studies that have been conducted regarding the growth of the pinto bean in different environments. One of these studies aims to determine the performance of the aforementioned plant under varying levels of soil moisture (Nleya, Slinkard, & Vandenberg, 2001). Six types of pinto bean plants, three determinate and three indeterminate, were planted and subjected to different watering conditions—some were introduced under irrigated conditions, while some were raised under well-watered conditions. The results of the study showed that the indeterminate pinto bean types performed better under the well-watered conditions. In addition, two of the indeterminate seed types, as well as one of the determinate pinto bean plants showed better levels of adaptation and performance when the plants were subjected to drought stress conditions.
The journal is informative in the sense that it gives insight on the behavior and growth of the pinto bean when it comes to moisture levels. Using different varieties of pinto bean is a nice addition to the experiment because it gives knowledge on how different varieties of pinto beans respond to certain conditions, thus showing that results may not be consistent even across members of the same species. However, using different varieties only serve to confound the results more—it does not give an overview on the behavior of pinto beans in general. Perhaps the author could focus on one variety instead, or use the same setups for all varieties. As for the results, it is explicitly made clear that the experimental variable was moisture levels which was controlled by drought levels, and they utilized the experiment efficiently.
The effect of pinto bean on drought stress has been touched upon in the previous study; a research exploring further on this topic was made by Beebe et al in 2013, in which they tested the adaptation of different beans to drought. In this study, the researchers reviewed several articles about the genotyping of certain P. vulgarisspecies and how they adapt to different conditions. It was found out that different varieties of the common bean have different responses to drought, some responding better to this environmental condition than others. A sister variety of P. vulgaris, P. acutifolius, is well-suited for dryland conditions. As for the pinto bean, it was found, it was found out that it does not respond well to dry climates. This should be of some concern; since these beans are grown in tropical countries, there is a possibility that there will be water shortage some of the time. While this study is very comprehensive and well-researched, it has little data when it comes to experimentation itself. Thus, it can be used as an extensive reference but does not give new insight to the subject matter itself. These results are consistent with Gholami et al’s stud, who used a methodology that uses Completely Randomized Technique as well. Unlike the former, this one incorporates statistical techniques, thus lending more evidence to the theory affect pinto bean growth.
Another study conducted regarding the water stress levels of the pinto bean was made by Aguilar-Benitez in 2014. In this study, they examined the two primary crops in Mexico, the maize and the common bean and their response in different water stress levels. They utilized a completely random design to introduce different levels of water levels in four cultivars of each species. It was concluded that the improved cultivars had a better germination time and resistance to lack of water, but a lower root length and biomass.Use of a statistical analysis such as the CRD give supporting evidence to the study, but the statistical assumptions have to be satisfied to make it credible. Other studies like the one conducted Brick et al (2008) further add credibility to the fact that drought can negatively affect the growth of plants, such as severely informdecreasing their output rate.
The conclusion of these studies proves that some cultivars of the pinto bean perform significantly better than others, as well as lead credibility to the response of the plant in the water content of the soil. This is especially important as the plants are usually planted in areas with wet and dry seasons. It is important how the plant would fare in the dry season given the lack of water. Based on the study, it is important to plant the improved cultivars when there is a limiting factor in the environment like lack of water.
A final study on the effect of irrigation on pinto beans was done by Dapaah, McKenzie and Hill (2000), in which they also found out that water levels is a major determining factor on the growth rate of the plant. However it should be noted that the study takes into account the local climate in the area of New Zealand, and thus the results for the study is largely applicable for places with a similar climate. Nevertheless, it gives credence to the fact that one of the soil conditions that largely affect the growth of the plants is the water content of the soil where the beans are planted upon.
Pinto Beans: Herbicides and Soil Temperature
Soil temperature is not one that would normally come to mind when soil conditions are discussed. Nevertheless, it is an important aspect that should not be overlooked, as it may cause a significant effect on plant growth. A study focusing on this factor, as well as the effect of herbicide, was made by Jeffery et al in 2008. The study revealed that different soil temperatures had an effect on the nutrient content of the soil, but if has no effect on the morphology of the plant whatsoever. Additionally, there are some herbicides which can cause a negative impact on the growth of the plant such as aciflourfen.
The factor that is taken under consideration in the study is interesting, as it reveals a new perspective on what could possibly affect the nutrients in the soil. The methods used aim to fully measure the effect of soil temperature, given that they do not only focus on its impact on the growth of the plant but also its morphology as well. In order to improve the research, perhaps a more credible statistical technique can be used. Another similar study made by Lozovaya et al (2004) which reveals that a lower temperature hastens a plant’s maturity, Like the above study, the research could be improved with the use of some statistical analysis to determine the relationship between the variables in question.
Quality of Pinto Beans
One way of determining the effect of certain factors in pinto beans is by observing the plants directly rather than letting them grow under controlled conditions. This is the gist of the study of Quenzer, Huffman, and Burns (2006) which aims to explore how some factors affect the quality of the pinto beans. They examined certain cultivars of pinto beans in Thrall and El Pso, Texas, and Twin Falls, Idaho, and their physical and chemical attributes were noted. It was found out that shear values was the primary determinant of the quality in the bean plants by using statistical analyses such as analysis of variance (ANOVA) and correlation analysis. In addition, the taste preference of the cultivators also influenced the variety of pinto beans that they will grow.
This is another study regarding pinto beans that can be used to provide an in-depth background of the plant in general. The environmental factors, such as the soil conditions in the aforementioned locations can be researched so as to give information on how this can affect the quality of the pinto bean. This can be a cost- and time-effective alternative method of growing the plants themselves under laboratory conditions. However, it comes with the side effect of having unknown confounding factors that can interfere with the results. The use of ANOVA was justified as the study was dealing with multiple populations. However, a regression analysis instead of correlation can better give information on the effect of certain factors on the quality of pinto bean, as well as determine whether or not they are insignificant. In addition, a regression analysis can reveal some interaction effects between the factors, which can be helpful in analyzing results.
Pinto Beans and Soil Content
The nutritional content of the soil can not only be a determinant of plant growth; it can also be a significant factor in other aspects of plant development as well. For example, the nutrition in the soil can help plants fight off plant diseases. For instance, Naseri (2014) conducted on how beans and the nutritional content of the soil they were planted in helps them grow resistant to fusarium root rot. The results of the study showed that pinto beans grow best at soil with low sand content, and they fare better if the soil is considered fertile. Additionally, plants that grow in soil with at moderate amount of sand have higher production yields and have a greater chance of not develop the root rot disease.
One noticeable method in the study is the use of Principal Component Analysis, a statistical component technique to determine what factors are significant when multiple variables are in question. Since the researchers considered many variables, it is best to use this king of statistical technique to accurately analyze and interpret the results. This also gives insight on what kind of soil the pinto bean should be planted, specifically the amount of sand. The focus on sand is explained by the hometown of the researcher, Iraq, which is known to be a sandy pace.
Pinto Bean and Some Elements
Cobalt can be classified as one of the nutrients in the soil that can have an effect on plant growth. Plants, however, react differently to cobalt—cobalt improves the growth of some plants, while in others the element is unnecessary. In general, cobalt is considered a useful plant nutrient, but ultimately not necessary for plant growth at all.
A study which aims to measure the effect of cobalt on the pinto bean was conducted by Sharafi et al in 2013. Using a Completely Randomized Design, they assigned pinto bean plants in pots with different cobalt concentrations: 0, 20, 70, 150 and 220 mg Co/kg dry soil respectively. The study reveals that for pinto beans, the tolerable amount of cobalt is at least 70 mg/kg of dry soil; any more than that and it will impact the pinto bean growth rate negatively.
The study yields a novel part of soil composition by examining the effect of a relatively niche element in the growth rate of the pinto bean. Usage of the completely randomized design makes for a better support of the results. However, the applicability of the study is debatable at large because as mentioned earlier, introduction of cobalt into the soil is overlooked in favor of more important nutrients such as potassium and the like. Still, it may be useful in some parts of the world where cobalt is a major component of the soil.
Perhaps a more important element, such as potassium, can yield better results. Nielsen, Eshel and Lynch aimed to study the effect of the potassium in beans, and found out that the rate of potassium in the soil has a great impact on growth of the plant. The growth rate was reduced by 20% if the phosphorus rate of the soil is medium, and a whopping 90% was lost to plant growth if the plant has low levels of potassium. While this study gives background on the effect of the nutritional content of the soil, it lacks quantitative data that extensively determines the effect of potassium on plant growth. A statistical technique, such as correlation, can yield these desired results.
Osuagwu et al (2015) analyzed how pinto beans grow under a specific type of soil: dump site soil. They found out that plants grow in an optimum level on such a kind of soil because it contains a huge amount of nutrients such as fat, protein content, and the like. However, it also contains lots of anti-nutritional content as well so this type of soil may not be suitable. The analysis of the nutritional content provides a depth into the study, and gives an explanation as to why plants grow well in dump site soil.
Conclusion
Pinto bean, being one of the staple beans in United States and Mexico, has been one of the plants of interest in the field of botany. Many studies have been done on this plant, each with varying results that give insight on the general behavior of the plant. So far it has been found out that pinto bean plants, like any other plant, reacts significantly to moisture content in the soil—drought levels can lower the quality and growth rate of the plant, while priming the plants by soaking it improves its growth rate. In addition, the nutrients in the soil affect the plant as well.
These studies can be used as background information on the study of the pinto bean. While there is comprehensive information about the plant, much still needs to be learned in order to fully understand the behavior of the pinto bean.
Literature Cited:
Aguilar-Benitez, G., C.B. Peña-Valdivia, J. R. Vega, R. Castro-Rivera, and H.M. Ramirez-Tobias. Seed germination and early root growth in common bean and maize landraces and improved cultivars at different water stress levels. International Journal of Applied Science and Technology 4: 118 – 127.
Ayalew, T. 2013. Effects of soil types and nutrient levels on early leaf development of maize, bean, and sunflower crops. African Journal of Agricultural Research 9: 1970 – 01974.
Beebe, S.E., I.M. Rao, M.W. Blair, and J. AAgosta-Gallegos. 2013. Phenotyping common beans for adaptation to drought. Front Physiology 4.
Brick, M. A. , J. B. Ogg, S. P. Singh, H. F. Schwartz, J. J. Johnson, and M.A. Pastor-Corrales. 2008. Registration of drought-toleratn, rust-resistant, high-yielding pinto bean germplasm line C046348. Journal of Plant Registrations 2: 120 -124.
Dapaah, H. K. B.A. McKenzie, and G. D. Hill. 2000. Influence of sowing date and irrigation on the growth and yield of pinto beans (Phaseolus vulgaris) in a sub-humid temperate environment. Journal of Agricultural Science 134: 33 -43.
Gholami, A., S. Sharafi, S. Ghasemi, and A. H. Sharafi. 2010. Pinto bean seed reserve utilization and seedling growth as affected by seed size, salinity and drought stress. Journal of Food Agriculture and Environment 7: 411 – 414.
Gill, J.S., J. Tisdall, Sukartono, I.G.M. Kusnarta, and B.M. McKenzie. 2004. Physical properties of a clay loam soil mixed with sand. Soil Aggregation and Structural Quality 14.
Jeffery, L.S., E. Nkwen-Tamo, L. R. Robison, and V. D. Jolley. 2008. Nutrient and growth response of pinto bean to foliar‐applied herbicides and soil temperatures. Journal of Plant Nutrition 10: 1345 – 1353.
Lovozaya, V.V., A. V., Lygin, A.V. Ulanov, R. L. Nelson, J. Dayde and J.M. Widholm. 2004. Effect of temperature and soil moisture status during seed development on soybean seed isoflavone concentration and composition. Crop Science 45:1934 -1940.
Nielsen, K.L., A. Eshel, and J.P. Lynch. 2000. The effect of phosphorus availability on the carbon economy of contrasting common bean (Phaseolus vulgaris L.) genotypes. Journal of Experimental Botany 52:328 -339.
Nleya, T.M., A. E. Slinkard, A. Vandenberg. 2001. Differential performance of pinto bean under varying levels of soil moisture. Journal of Plant Science 81: 233 – 239.
Osuagwu, G. G T., O. Nwokeocha, G. C. Mgbeze, and O.O. Ini,2015. Effect of Dump Site Soil on the Growth of Common Bean (Phaseolus vulgaris). International Journal on Plant Science and Ecology 1, 213 -217.
Passioura, J.B. 2002. ‘Soil conditions and plant growth’. Plant, Cell & Environment 25:311 -318.
Sharafi, M., A. Ranjbar, B. Harchegani, R. Iranipour. 2013. Effect of soil cobalt concentrations on some growth indices of pinto bean. Iranian Journal of Soil Research 27: 85 – 96.
Whitmore, A. P. and W. R. Whalley. 2009. Physical effects of soil drying on roots and crop growth. Journal of Experimental Botany 60: 2845 – 2857.
