**3. Selecting sugarcane variety**

*Multifunctionality and Impacts of Organic and Conventional Agriculture*

(product/input).

In sugarcane, it is common to evaluate the results obtained by quantifying the production of culms, sugars, or total shoot biomass. In analyzing the production costs, one can use the exchange ratio, which is an economic indicator that shows the exchange capacity of a certain product in relation to the inputs used in production

of time, so that the extent of the variation in results can be measured.

decreases in yield over seven cycles (seven cuts).

the worker will be more exposed to snakes and scorpions.

The great advantage of exchange ratio analysis over price analysis is that agricultural products represent the weighted average of several inputs and goods used by the farmer. Thus, it is easier to calculate the variation in producer purchasing power or production system efficiency. If possible, this analysis should cover a long period

**Table 2** shows that to feed 25 cows for 365 days (20 kg of natural matter per cow/ day), an area of 1.63 ha of a sugarcane plantation with high yield in the plant-cane cycle and 10% decrease in subsequent cycles would be necessary (Scenario 1). On the other hand, an area of about 3.3 ha would be needed for a sugarcane plantation with medium yield in the plant-cane cycle and large decreases in subsequent cycles (Scenario 14). In sugarcane plantations with yields of less than 60 tons of natural matter per ha (about 50 tons of industrializable culms), in addition to decreasing the use of land and labor resources, chemical weed control is generally inefficient, as the crop does not completely cover (shade) the soil, allowing the emergence and growth of invasive species (**Figure 1**). Also, in cases where sugarcane is cut by hand,

*Contrast between a sugarcane plantation with high yields and excellent weed control, and a plantation with* 

The use of spreadsheets (e.g., Excel) is helpful in analyzing simulation results, as well as budgeting and managing sugarcane production costs. The authors have guided farmers to adopt practices that recover and maintain soil fertility, recycle nutrients, and reduce compaction and sealing of the topsoil, combined with activities that enable increased yields in plant-cane and small decreases in subsequent cycles. **Table 2** shows a simulation of sugarcane yield in 14 scenarios, which combine high and medium yields in the plant-cane cycle to low, medium, or high

**22**

**Figure 1.**

*low yields and poor weed control.*

Choosing the right variety is an important and low-cost technology for the producer. Currently, there are several sugarcane cultivars with proper agronomic and zootechnical characteristics, such as high response to improved soil fertility, erect growth, and resistance to falling, which facilitates harvesting, high culm and sucrose yield, regrowth vigor, resistance to pests and diseases, and good dry matter digestibility.


*1 Yield: Yield per ha of industrializable culms and biomass (High, Medium or Low)*

*2 Harvest: Recommended months for the harvest of sugarcane for brown sugar and rapadura*

*3 Soils: Soil fertility requirement (High, Medium or Low)*

*4 Regrowth: sprout vigor of regrowth under conditions of trampling by machines or animal traction vehicles*

*5 Tillering: growth speed and soil shading, thus minimizing weed competition*

*6 Toppling: plant growth habit, which varies from erect to decumbent. Even cultivars with upright culms may topple under high-yield conditions*

*7 Detrashing: removal of dry leaves or attachment of the sheath to the culm*

*8 Sensitivity to certain herbicides*

*9 Diseases of the plant shoot.*

*Source: Silveira, L. C. I. (unpublished data).*

#### **Table 3.**

*Agroindustrial, morphological, and tolerance characteristics of seven varieties of sugarcane recommended for cultivation in the small farms of the Zona da Mata region.*

The authors of this chapter do not recommend planting one variety of sugarcane in more than 33% of the total area, even if it has a large number of desirable characteristics. This is because sugarcane production will be greatly compromised in cases of possible breakdown of resistance to disease or sudden decline of the cultivar. Thus, in order to obtain a good quality product, ensure vigorous regrowth and consequently increase the longevity of the sugarcane plantation, the authors recommend that farmers use at least four varieties of sugarcane and adopt measures to maintain soil fertility and cut the sugarcane at the most suitable time for each variety. Once the varieties have been selected, it is necessary to check the quality of the seedlings. It is also important to confirm the health of the seedlings in terms of diseases, pests, and mixture of other cultivars. **Table 3** shows characteristics of the varieties currently most planted in small farms of the Zona da Mata region.

RB867515 has been the variety of sugarcane most cultivated by small producers due to its high yield potential in different edaphoclimatic conditions. As mentioned in **Table 3**, RB867515 is a medium maturing variety with high sucrose content in industrializable culms. It has a low requirement for soil fertility, but it is very responsive to fertilization. Its detrashing is easy and it has no pilosity. **Figure 2** shows dry matter accumulation rate in shoots of three sugarcane varieties (RB855536, RB867515, and SP801816). The study was conducted in soil of medium texture in the city of Mercês, state of Minas Gerais (MG) (latitude 21.260232, longitude 43.298827, and altitude 503 m).

Sugarcane was planted in the first half of February. Following the recommendation of Ref. [1], 5.0 t of dolomitic limestone and 1.5 t of gypsum were applied per ha in September of the year prior to the planting of sugarcane. The soil was plowed and harrowed, followed by the sowing of *Crotalaria juncea*. In early February, at the grain filling stage, *Crotalaria juncea* was incorporated into the soil. A week later, the soil was furrowed and sugarcane was planted. The chemical fertilization consisting solely of phosphorus was applied at the bottom of the planting furrow at a dose of 100 kg of phosphorus per ha (equivalent to 229 kg of P2O5 per ha). Chemical weed control with pre-emergent herbicide was used. In mid-September, when the rainy season started again, 200 kg of potassium per ha (equivalent to 240 kg of K2O per ha) was applied between the rows of sugarcane. Assessments of dry matter

#### **Figure 2.**

*Dry matter accumulation rate in shoots of three sugarcane varieties planted in February and harvested in July of the following year. Study carried out in the city of Mercês, located in the Zona da Mata region. Source: Oliveira MW (unpublished data).*

**25**

deficiency or toxicity in previous crops.

*Sugarcane Production Systems in Small Rural Properties DOI: http://dx.doi.org/10.5772/intechopen.84975*

industrializable culms more than the other two varieties.

**4. Implantation of sugarcane plantation**

accumulation were held in April, September, and December of the year of planting of sugarcane and in February, April, and July of the following year. As shown in **Figure 2**, RB867515 produced about 5.0 t more dry matter than the other two varieties, which corresponds to approximately 15 t of forage per ha. The average percentage of culms in forage of these varieties is 85%. Thus, RB867515 produced 12 t of

Similarly to South Central Brazil, the planting of sugarcane without irrigation in small farms of the Zona da Mata region is essentially done at the beginning of the rainy season (September and October) and at end of the rainy season (February to March). The sugarcane planted at the beginning of the rainy season can be harvested from April to May of the following year (known as "one-year sugarcane"). However, for sugarcane planted from February to March, the harvest will take place

The authors have recommended the planting of "one-year sugarcane" in more fertile soils with smoother and less erosive relief, because there is heavy rainfall during this period. Because sugarcane starts the maximum growth phase in January (when water and thermal availability begin to decrease), nutrient supply should not be a limiting factor to plant development. Therefore, biomass yields exceeding 120 t of natural matter per ha should be reached. However, planting "one-and-a-half-year sugarcane" has been recommended for the more rugged and less fertile soils, since sugarcane will continue to grow in the field for a longer period. Also, the maximum growth phase (**Figure 2**) coincides with the times of greater water and light availability, which results in higher vegetation cover by sugarcane foliage as well as in higher photosynthetic rate and dry matter accumulation. One other great advantage of planting the "one-and-a-half-year sugarcane" is the possibility of growing *Crotalaria juncea* prior to the planting of sugarcane.

about 15–18 months after (known as "one-and-a-half-year sugarcane").

**5. Evaluation of soil fertility and lime and gypsum application**

Sugarcane extracts and accumulates large amounts of nutrients from the soil because it produces large amounts of biomass. In evaluations carried out in small properties of the Zona da Mata region, the authors found that to produce 120 tons of natural matter per ha (about 100 t of industrializable culms), the accumulation of nutrients in shoots is approximately 150, 40, 180, 90, 50, and 40 kg of N, P, K, Ca, Mg, and S, respectively. In the case of iron, manganese, zinc, copper, and boron, accumulation in shoot biomass for a production of 120 t is around 8.0, 3.0, 0.6, 0.4, and, 0.3 kg, respectively [1]. Because of this high nutrient removal, it is necessary to know the nutrient supply capacity of the soil to complement it with fertilization if necessary. On the other hand, if toxic levels are found, the concentration of these elements is reduced by applying limestone and gypsum. The availability and presence of toxic levels of nutrients in soil are typically evaluated by chemical analysis of the topsoil. Knowledge of the history of the area is also of great value, especially fertilization and whether or not there were symptoms of

Soil samples are typically collected at depths of 0–20 and 20–40 cm. The results of the analysis at 0–20 cm have been used to calculate the need for fertilization and liming, while those at 20–40 cm to calculate the need for gypsum. Because these are small areas, the authors have advised producers to collect soil samples using a hole

*Multifunctionality and Impacts of Organic and Conventional Agriculture*

The authors of this chapter do not recommend planting one variety of sugarcane in more than 33% of the total area, even if it has a large number of desirable characteristics. This is because sugarcane production will be greatly compromised in cases of possible breakdown of resistance to disease or sudden decline of the cultivar. Thus, in order to obtain a good quality product, ensure vigorous regrowth and consequently increase the longevity of the sugarcane plantation, the authors recommend that farmers use at least four varieties of sugarcane and adopt measures to maintain soil fertility and cut the sugarcane at the most suitable time for each variety. Once the varieties have been selected, it is necessary to check the quality of the seedlings. It is also important to confirm the health of the seedlings in terms of diseases, pests, and mixture of other cultivars. **Table 3** shows characteristics of the

varieties currently most planted in small farms of the Zona da Mata region.

ers due to its high yield potential in different edaphoclimatic conditions. As mentioned in **Table 3**, RB867515 is a medium maturing variety with high sucrose content in industrializable culms. It has a low requirement for soil fertility, but it is very responsive to fertilization. Its detrashing is easy and it has no pilosity. **Figure 2** shows dry matter accumulation rate in shoots of three sugarcane varieties (RB855536, RB867515, and SP801816). The study was conducted in soil of medium texture in the city of Mercês, state of Minas Gerais (MG) (latitude 21.260232,

was applied between the rows of sugarcane. Assessments of dry matter

*Dry matter accumulation rate in shoots of three sugarcane varieties planted in February and harvested in July of the following year. Study carried out in the city of Mercês, located in the Zona da Mata region. Source:* 

longitude 43.298827, and altitude 503 m).

RB867515 has been the variety of sugarcane most cultivated by small produc-

Sugarcane was planted in the first half of February. Following the recommendation of Ref. [1], 5.0 t of dolomitic limestone and 1.5 t of gypsum were applied per ha in September of the year prior to the planting of sugarcane. The soil was plowed and harrowed, followed by the sowing of *Crotalaria juncea*. In early February, at the grain filling stage, *Crotalaria juncea* was incorporated into the soil. A week later, the soil was furrowed and sugarcane was planted. The chemical fertilization consisting solely of phosphorus was applied at the bottom of the planting furrow at a dose of 100 kg of phosphorus per ha (equivalent to 229 kg of P2O5 per ha). Chemical weed control with pre-emergent herbicide was used. In mid-September, when the rainy season started again, 200 kg of potassium per ha (equivalent to 240 kg of K2O per ha)

**24**

**Figure 2.**

*Oliveira MW (unpublished data).*

accumulation were held in April, September, and December of the year of planting of sugarcane and in February, April, and July of the following year. As shown in **Figure 2**, RB867515 produced about 5.0 t more dry matter than the other two varieties, which corresponds to approximately 15 t of forage per ha. The average percentage of culms in forage of these varieties is 85%. Thus, RB867515 produced 12 t of industrializable culms more than the other two varieties.
