140
Since most nutrient concentrations in maize stover in different demonstration
sites were rather not significantly (P < 0.5) different between YSS and FP, it means
that most farmers who feed the whole maize stover without bringing back the
manure to the crop field end up in soil plant nutrient mining every year, and this
leads to reduced crop productivity and increased household food insecurity.
Therefore, smallholder crop-dairy cattle farmers should be trained on efficient use
of maize stover for sustainable intensification of agricultural production in their
respective areas.
3.3 The Chemical Composition of the Rice Straw
from Different Demonstration Sites
The mean chemical compositions of the rice straw from different demonstration
sites and years are shown in Table 7. The improved agronomical practices had no
significant (P > 0.05) effect on rice straw macro- and micronutrient concentrations. Except for K (Fig. 3), all other macronutrients in rice straw were too low
to support growth, production and reproduction of cattle. However, such low
macronutrient values of rice straw have also been reported elsewhere (Singh
et al. 1995; Sath et al. 2013). Farmers who use rice straw as bulk feed for their
animals are advised to supplement it with mineral licks to sustain their productivity. Rice straw is chaffed and fed as basal diet in most areas where green forage is rather scarce, especially in the dry season. The low N concentration
ranging from 0.48% to 0.84% and the high lignin content (>8%) and silica content in the leaf (ranging from 8% to 14%) are in agreement with Singh et al.
(1995) and Abd-Talib et al. (2018). The low N content may reduce the digestibility to improve their digestibility of the rice straw, treatment with urea, urea
with lime or alkaline hydrogen peroxide is important. Also, supplementation
with protein as an energy source to encourage and increase utilisation efficiency
can be effective (Mo et al. 2008). High K content in rice straw signifies the need
to train the smallholder rice growers not to remove all the rice straw from the
fields (Mtengeti et al. 2016).
Generally, YSS has an insignificant impact for most of the micronutrient concentration of rice straw in several demonstration sites (Table 7, Figs. 3 and 4). An
exception was for Cu, which was depressed by YSS treatments in Mkula village
in 2012 and 2014, but was improved in Dihombo in 2013 and 2014. Another
micronutrient that was lowered by YSS treatments was Zn in Mkula in 2013 and
Dihombo in both short and long rainy seasons of 2013 and long rains of 2014. The
two minerals, Cu and Zn, which are essential for cattle reproduction, were also
reported deficient in Dihombo. Interestingly, dairy cattle had long calving interval
in this village (Mtengeti et al. 2008; Phiri et al. 2008). Except for Fe and Mn, all
other assessed micronutrients were rather low to support growth, production and
reproduction of cattle. There is a need for strategic effort to improve rice straw
E. J. Mtengeti et al.
Since most nutrient concentrations in maize stover in different demonstration
sites were rather not significantly (P < 0.5) different between YSS and FP, it means
that most farmers who feed the whole maize stover without bringing back the
manure to the crop field end up in soil plant nutrient mining every year, and this
leads to reduced crop productivity and increased household food insecurity.
Therefore, smallholder crop-dairy cattle farmers should be trained on efficient use
of maize stover for sustainable intensification of agricultural production in their
respective areas.
3.3 The Chemical Composition of the Rice Straw
from Different Demonstration Sites
The mean chemical compositions of the rice straw from different demonstration
sites and years are shown in Table 7. The improved agronomical practices had no
significant (P > 0.05) effect on rice straw macro- and micronutrient concentrations. Except for K (Fig. 3), all other macronutrients in rice straw were too low
to support growth, production and reproduction of cattle. However, such low
macronutrient values of rice straw have also been reported elsewhere (Singh
et al. 1995; Sath et al. 2013). Farmers who use rice straw as bulk feed for their
animals are advised to supplement it with mineral licks to sustain their productivity. Rice straw is chaffed and fed as basal diet in most areas where green forage is rather scarce, especially in the dry season. The low N concentration
ranging from 0.48% to 0.84% and the high lignin content (>8%) and silica content in the leaf (ranging from 8% to 14%) are in agreement with Singh et al.
(1995) and Abd-Talib et al. (2018). The low N content may reduce the digestibility to improve their digestibility of the rice straw, treatment with urea, urea
with lime or alkaline hydrogen peroxide is important. Also, supplementation
with protein as an energy source to encourage and increase utilisation efficiency
can be effective (Mo et al. 2008). High K content in rice straw signifies the need
to train the smallholder rice growers not to remove all the rice straw from the
fields (Mtengeti et al. 2016).
Generally, YSS has an insignificant impact for most of the micronutrient concentration of rice straw in several demonstration sites (Table 7, Figs. 3 and 4). An
exception was for Cu, which was depressed by YSS treatments in Mkula village
in 2012 and 2014, but was improved in Dihombo in 2013 and 2014. Another
micronutrient that was lowered by YSS treatments was Zn in Mkula in 2013 and
Dihombo in both short and long rainy seasons of 2013 and long rains of 2014. The
two minerals, Cu and Zn, which are essential for cattle reproduction, were also
reported deficient in Dihombo. Interestingly, dairy cattle had long calving interval
in this village (Mtengeti et al. 2008; Phiri et al. 2008). Except for Fe and Mn, all
other assessed micronutrients were rather low to support growth, production and
reproduction of cattle. There is a need for strategic effort to improve rice straw
E. J. Mtengeti et al.