Biomass production and nutrient use efficiency in white Guinea yam (Dioscorea rotundata Poir.) genotypes grown under contrasting soil mineral nutrient availability

Abstract

Yam (Dioscorea spp.) is of great importance to food security, especially in West Africa. However, the loss of soil fertility due to dwindling fallow lands with indigenous nutrient supply poses a challenge for yam cultivation. This study aimed to determine shoot and tuber biomass and nutrient use efficiency of white Guinea yam (Dioscorea rotundata) grown under low- and high-NPK conditions. Six white Guinea yam genotypes were used in field experiments conducted at Ibadan, Nigeria. Experiments were conducted with low soil NPK conditions with zero fertilizer input and high soil NPK conditions with mineral fertilizer input. Differences in response to soil NPK conditions, nutrient uptake, and nutrient use efficiency (apparent nutrient recovery efficiency) were observed among the tested genotypes. The genotypes TDr1499 and TDr1649, with high soil fertility susceptibility index (SFSI>1) and an increase in shoot and tuber biomass with fertilizer input, were recognized as susceptible to soil NPK conditions. There was a marked difference in apparent nutrient recovery efficiency; however, there was no varietal difference in physiological efficiency. Differences in apparent nutrient recovery efficiency among genotypes affected the fertilizer response (or susceptibility to soil NPK conditions) and the nutrient uptake. In contrast, the genotype TDr2029, with SFSI<1 and low reduction in shoot and tuber production between non-F and +F conditions, was recognized as a less susceptible genotype to soil NPK status. It was revealed that NPK fertilization did not reduce tuber dry matter content, regardless of genotype differences in susceptibility to soil NPK conditions. Hence, this could be helpful to farmers because it implies that yield can be increased without reducing tuber quality through a balanced application of soil nutrients. Our results highlight genotypic variation in sensitivity to the soil NPK availability, nutrient uptake, and nutrient use efficiency white Guinea yam. Differences in susceptibility to soil NPK conditions could be due to the genotypic variations in nutrient recovery efficiency white Guinea yam. Our findings could contribute to breeding programs for the development of improved white Guinea yam varieties that enhance productivity in low soil fertility conditions with low and high-input farming systems.

Effect of Mineral Fertilisation on Tuber Yield and Quality in Yams (Dioscorea alata and Dioscorea rotundata)

“…The experimental plots had low-fertility soil [26], to which chemical fertilisers were applied to increase yam tuber yields. Plant responses to fertilisation varied among the genotypes tested (Table 2), suggesting that the effect of fertilisers on tuber yield can be genotype-specific, although these results were consistent with those reported in previous studies [30][31][32][33][34]. The fertiliser had different effects on fresh and dry tuber weights among the genotypes (Table 2); Danacha, Ojuiyawo, and TDa0200012 responded positively to fertilisation, which was predicted to improve productivity if applied to low-fertility soil conditions.…”

“…The fertiliser had different effects on fresh and dry tuber weights among the genotypes (Table 2); Danacha, Ojuiyawo, and TDa0200012 responded positively to fertilisation, which was predicted to improve productivity if applied to low-fertility soil conditions. It is suggested that Danacha, Ojuiyawo, and TDa0200012 exhibit superior Fertiliser absorption capacity compared to other genotypes, resulting in enhanced nutrient uptake and, consequently, higher tuber yields [32,34].…”

Changes in the rhizosphere and root-associated bacteria community of white Guinea yam (Dioscorea rotundata Poir.) impacted by genotype and nitrogen fertilization

“…The six white Guinea yam genotypes (S004, S020, S032, S042, S058, and S074) were cultivated in the experimental field (N 7°30′, E 3°54′) of the International Institute of Tropical Agriculture (IITA, Ibadan), Nigeria, in 2018. These six genotypes are part of the mini-core collections of white Guinea yam and exhibit varying tuber yield and leaf density [ 6 , 27 ].…”

“…Matsumoto et al [ 6 ] reported that these genotypes exhibited identical behavior in field-cultivated experiments and have been used to determine shoot and tuber biomass as well as nutrient use efficiency in white Guinea yam. Consequently, we also used these six genotypes in our study, and the experimental design is presented in Supplementary Table 1 .…”

“…Yam, by tradition, is a nutrient-loving plant generally referred to as “the first crop after bush fallow" due to its nutritional requirements [ 5 ]. However, yam yield and productivity in response to soil fertility vary from one genotype to another [ 6 ]. Furthermore, the available information on fertilizer use in yam cultivation is minimal and regionally based.…”